Multi-enzyme co-immobilization systems, in which two or more enzymes are immobilized onto or into the same carrier, are based on enzyme cascade reactions. Due to their high atomic economy and sustainable utilization properties, such systems have become a research hotspot in various fields such as material science, life science, and biomedicine. Selecting suitable carrier materials is the most basic and important way to improve the catalytic efficiency of multi-enzyme co-immobilization system. In this paper, the cascade reaction consisted of glucose oxidase and horseradish peroxidase was used as the model reaction, and the current research progress of carriers for multi-enzyme co-immobilization was summarized from three different interaction forms between carriers and enzymes: random immobilization, partition immobilization and directional immobilization, respectively. Finally, in order to provide research ideas for more multi-enzyme co-immobilization systems, the limitations and challenges in this field were analyzed.

Reductive amination of alcohol is one of the most effective and promising methods for the synthesis of amine, and the high-performance catalyst is the core. The progress in homogeneous catalysts of Ru, Ir, Pd, Cu, and nonmetallic ones and heterogeneous catalysts of Co, Ni, Ru, Pd, et al. for reductive amination of alcohols was outlined in detail respectively in this paper. The catalytic performance and reaction regularity of different catalytic systems were discussed together with their respective characteristics and limitations. Finally, it is pointed out that the application of homogeneous catalytic system is limited by the recovery problem. The research should focus on the development of efficient and cheap catalytic systems, the expansion of their applications and the recovery of the catalyst. The heterogeneous reaction catalysts are of high specificity and the performance is difficult to meet the need of industrial application. The studies on the microstructure and the reaction mechanism of high performance catalyst, flow field state and process of high pressure system should be strengthened to improve the activity, selectivity and stability of the catalysts.

To meet the requirements of sustainable development, photoelectric catalytic decomposition of hydrogen in the water, CO₂ reduction and degradation of pollutants, has become the research hot spot due to its predictability of advantage in energy storage and transport. Metal-organic frameworks (MOFs) material with high specific surface area, metal/organic ligand rich, large pore volume, structure and composition of the advantages of adjustable, has great potential in photoelectric catalysis applications. Therefore, this article mainly reviewed the research progress on the application of MOFs materials in the photoelectric catalysis from the three aspects of hydrogen production from water decomposition, CO₂ reduction and organic pollutants degradation. Firstly, the MOFs materials were introduced in the field of catalysis in recent years. Several widely used MOFs catalyst synthesis methods were summarized, and their advantages and disadvantages were compared. Secondly, a few basic mechanisms and the latest research progress in the application of MOF based photoelectric catalyst was introduced in detail respectively. Finally, the role of MOFs materials in optical electrode and the opportunities and challenges in the field of photoelectric catalysis was carried on the brief summary and outlook.

Microcapsule technology is a new technology with rapid development, and has been successfully applied in biomedicine, food, chemistry, and other fields for its several advantages, including accurate drug administration and controlled content release. Sodium alginate is a unique plant polysaccharide extracted from marine algae, and has been widely used as microcapsule coating materials owing to its good solubility, good film-forming and gelation performance. However, there are still some problems in the manufacture of sodium alginate microcapsules, such as imperfect formula and unstable preparation process, due to the properties of sodium alginate microcapsules being difficult to control and easily affected by base material, cross-linking agent, and process parameters. In order to solve the above problems, the properties of sodium alginate, such as ion exchangeability, pH susceptibility, gelling characteristics, and influencing factors in the preparation process of microcapsules were summarized in this review, and the application of sodium alginate microcapsules in encapsulating cells, drugs, and essential oil were discussed as well. It is pointed out that the future research direction should focus on improving the preparation process of microcapsules, clarifying the relationship between film-forming mechanism and mechanical properties of sodium alginate gel, enhancing the strength and toughness of sodium alginate microcapsules, and promoting the formulation research of sodium alginate with other polymer materials,thereby expanding the application range of sodium alginate microcapsules and accelerating the industrialization process of sodium alginate microcapsules.

Fluoride molten salt has many advantages, such as high temperature stability, high thermal conductivity,large heat capacity,wide electrochemical window,low saturated vapor pressure and small neutron absorption cross section. It is an important functional material which has found widespread applications. The typical preparation and purification methods of fluoride molten salt, including vacuum dehydration, fluorination using ammonium fluoride, H₂-HF purification, electrochemical purification and reduction with metals, are introduced in detail. The mechanism and technical characteristics are analyzed for the different methods that are used to remove impure ions in molten salt. At the same time, the applications and progress of fluoride molten salts in nuclear energy, metallurgy, functional materials preparation, advanced energy storage medium, surface treatment technology, electronic chemicals, fine chemicals and molten salt battery materials are reviewed. The fluoride molten salts are mainly used as the nuclear reactor coolant, molten salt electrolyte, high temperature energy storage material and reaction medium. The existing problems in this area are also discussed. It is important to study and clarify the preparation and purification mechanism of fluoride molten salt, to explore the existence form and impurity migration nature in the process of fluoride purification, and to develop a new method for the purification of the molten salt to reduce its corrosion and cost.

Distillation is the most widely used key separation technology in chemical engineering,which has been extensively used in separation process in industry,such as petroleum,chemical engineering,fertilizer,pharmaceutical,environment protection,etc. Distillation possesses extensive application and technical mature,but also faces some disadvantages as huge capital investment and high energy consumption. Thus,it is of significant social-economic meanings to research and develop new as well as high-efficient mass transfer unit and develop new energy-saving distillation technique. The research progress of distillation process is summarized in this article,including types of distillation column,hydraulic performance,mass transfer performance,scale-up,energy saving,process intensification,etc. For hydraulic performance of tray column,the gas-liquid flow situation,pressure drop,weeping and entrainment are introduced. For hydraulic performance of packing column,pressure drop,flooding and holdup are studied. But the current study is still relying on empirical correlation and lack of the rigorous theoretical model. As for the study of gas-liquid mass transfer,the mass-transfer theory is mainly reviewed,but the scientific and accurate model has not been put forward. The study of scale-up includes tray,gas-liquid distributor and support device. The process energy-saving and intensification technology is reviewed,including process- coupling,process energy-saving,recovery of low grade waste heat,special distillation. Finally,the prospects of mass-transfer,process intensification and development direction of process integration are proposed.

UiO-66 is a typical Zr-based metal-organic framework with large surface area, high porosity, and adjustable micro-pore size and is easily functionalized. Unlike most MOFs, UiO-66 exhibits excellent chemical stability, mechanical stability, thermal stability and water resistance, indicating great application prospect in the fields of adsorption and catalysis. In this paper, the synthesis methods of UiO-66 were introduced in detail, including solvothermal, mechanochemical, microwave-assisted, continuous flow and dry-gel conversion methods. The dry-gel conversion method has the advantages of high yield, simple purification & activation process and no organic waste production, showing great potential in commercialization. Progress on modified UiO-66 materials in the field of adsorption of toxic industrial chemicals and catalytic degradation of chemical warfare agents has been reviewed, and an outlook on the development trend of electrospun nanofiber supported UiO-66 in the field of chemical protection was made.

Deep eutectic solvents are also called deep eutectic mixtures or low transition temperature mixtures. As a novel class of ionic liquid analogues, deep eutectic solvents have become more and more popular in many fields due to their unique physical and chemical properties, low cost, simple preparation process, non-toxicity, negligible vapor pressure, biodegradability, which are also tunable to achieve specific functionality by adjusting their constituents and compositions. In this paper, the common hydrogen bond donor and acceptor units as well as the classification of deep eutectic solvents are introduced. And the latest research progress on the formation mechanism of deep eutectic solvents and their applications as extracting agents, solvents and catalysts in the field of extraction and organic reaction, such as esterification, Fridel-Crafts, cyclization, condensation and multicomponent reaction are summarized. Also, the existing problems and solutions in developing deep eutectic solvents are discussed. Deep eutectic solvents will be a promising new generation of solvents and catalysts thanks to their adjustable structures and functions.

TiO₂ has such advantages as excellent photocatalytic performance,high chemical stability,low toxicity and price. However,it only responds to UV light due to its wide forbidden band,and the electrons and holes are prone to recombination,leading to a decrease of catalytic activity and efficiency. This paper introduced the latest research progress on several main modification methods of TiO₂. Surface deposition of noble metal,semiconductor composite and dye sensitization can reduce the width of the forbidden band,increase the response wavelength and make full use of the sunlight. Ion doping can make TiO₂ crystal surface generate the defects,restrain the recombination of photoproduction electrons and holes,and increase the number of surface active centers. Carbon nanotube and graphene modification can improve light absorption of TiO₂ to the visible,extend the response range, speed up the electronic transmission,reduce the carrier recombination,and upgrade the catalytic efficiency. As a new doping material graphene has great potentials,and TiO₂-based multi-components composite photocatalysts are promising to achieve better catalytic properties than single-component surface modified or doped TiO₂. Finally,research progress on hydrophilic/hydrophobic surface modification of TiO₂ was reviewed.

Researches of the mechanism, process and catalysts for various olefin hydration reactions were reviewed. The latest progress in the processes and catalysts of cyclohexene hydration to produce cyclohexanol, propylene hydration to produce isopropanol, and high-carbon olefin hydration to produce high-carbon alcohol were summarized in detail, together with the development trend of olefin hydration reaction in the future. The reaction pathways of olefin hydration could be mainly divided into direct and indirect ones, and the reaction mechanisms were mainly the electrophilic addition mechanism of martensitic rule, the electrophilic addition mechanism of anti-martensitic rule and the radical mechanism. The olefin hydration catalysts are changing from liquid acid, alkali, transition metal salt or oxygen salt, to molecular sieve, solid acid, synthetic resin, photocatalyst and enzyme catalyst. In the future, photocatalysis and enzyme catalysis will be the key research directions of olefin hydration technology, and the optimization of reaction equipment parameters, the enhancement of catalyst performance, and the improvement of material mixing and mass transfer are the development trends of olefin hydration process optimization.

Hydrogen, as a clean and efficient secondary energy, is an important component of building a clean society in the future. To date, the hydrogen production industry in China is highly dependent on fossil energy. Therefore, the development of environment-friendly hydrogen production by water electrolysis has very important practical significance. The production of high-purity hydrogen through the electrolysis of water via renewable energy is one of the most potential green hydrogen route among many hydrogen production technologies. Based on the introduction of three water electrolysis technologies and core components, the progress of the research on electrocatalysts for hydrogen evolution reaction (HER) was reviewed, and the research status of transition metal-based electrocatalysts and single-atom catalysts were systematically discussed. Furthermore, the integration of renewable energy generation and water electrolysis hydrogen production technology was further discussed, and the development progress of domestic and foreign hydrogen production projects based on renewable energy was briefly described. With the reduction of electricity costs and the development of efficient, stable and economical hydrogen evolution catalysts, hydrogen production by electrolysis based on renewable energy will be an important way for our country to realize the transition from traditional energy to low-carbon clean energy, solve the problem of renewable energy consumption, and accelerate the industrialization of hydrogen energy.

In this review,state-of-the-art technology of polyolefin-based elastomer manufacture,including major producers and product trademarks,grades and properties were summarized. Research and developments on production process and catalyst system for the ethylene-propylene binary and ternary rubbers(EPM,EPDM,mEPDM),the poly(ethylene-co-α-olefin) elastomer(POE)and the poly(ethylene-block-α-olefin) elastomer(OBC)were also introduced. It has been pointed out that the thermoplastic elastomer,such as POE and OBC,and the polyolefin plastomer not only had excellent mechanical and physical properties of polyolefin-based elastomer,but also was easy molding and processing,and can be recycled and reused. And the metallocene catalyst had the advantages of high activity,good ability to catalyze copolymerization with α-olefin,and single active site. In order to independently develop the polyolefin-based elastomer,the thermoplastic elastomer and plastomer with more excellent performance and more profitable,such as mEPDM,POE and OBC et al,the researches on the metallocene catalyst with high temperature adaptability and the high temperature solution polymerization process must be strengthened.

Biosynthesis of chemicals has the advantages of high efficiency, green and sustainable development. Acetyl coenzyme A, as an important intermediate of cellular metabolism in cells, is an important precursor for the synthesis of many biochemicals, and has played a vital role in the process of microbial carbon metabolism. Here we reviewed the synthesis and strategies of metabolic regulation of acetyl coenzyme A in Escherichia coli and its important applications. We also summarized the synthesis pathway of acetyl coenzyme A and the recent development of metabolic regulation strategies to increase the intracellular metabolic flux of acetyl coenzyme A production, these including metabolic regulation of the acetyl coenzyme A synthesized by acetic acid and pyruvate, metabolic regulation of the central carbon metabolic pathway and acetyl coenzyme A synthesized by beta oxidation pathway, and discovery of new pathways for acetyl coenzyme A synthesis. Finally, we prospected the feasible strategies of increasing acetyl coenzyme A supply and discussed methods of constructing cell factories for synthesizing acetyl coenzyme A as precursor chemicals by genome editing technology.

MXene is a graphene structured layered 2D nanomaterial with high electrical conductivity and large specific surface area, which is commonly used in energy storage. MXene is rich in end-group functional groups, which efficiently facilitated the formation of cross-linked structures with biomass based nanomaterials and then widen the layer spacing of MXene, thus improving the flexibility of devices and providing more ion transport channels. Therefore, the use of MXene in biomass energy storage nanomaterials is becoming a hot topic of research. This paper reviews the recent applications of MXene combining biomass based nanomaterials in the fields of energy storage. Firstly, the various MXene preparation methods and their advantages/disadvantages are introduced. Secondly, the optimized modifications of MXene energy storage devices with CNF, BC, CNC and other materials are presented, respectively. Then, the physical/chemical characteristics and the performance advantages of the three cutting-edge energy storage devices of supercapacitors, nanogenerators and secondary batteries derived from MXene-biomass based nanomaterials are also summarized, followed by emphatically focusing on the functions of biomassbased nanomaterials in MXene-biomass based nanocomposites. Finally, the challenges faced by MXene composited with biomass based nanomaterials in the energy storage areas and their future applications are analyzed and prospected.

Layered double hydroxide (LDH) are a kind of promising special multifunctional layered materials, which have the excellent regulatable capability, perfect environmental compatibility and remarkable efficiency, so they have been studied extensively in environmental protection, catalysis, energy storage, transducer and other fields. Most researches are conducted on the improvement of tailored synthesis methods and application of LDH, whereas the research on the transformation of LDH (composition, structure and morphology)is rare, especially on the general formation mechanism of LDH. The controllable preparation and in-depth applications of LDH with unique morphology and specific composition are highly demanded. An overview and comparison are presented on the interpretations of primary LDH laminate formation mechanisms which are the existence of divalent metal hydroxide, the existence of trivalent metal hydroxides and the direct topological phase transition mechanism. The solid-liquid and liquid-liquid reactions are thought to play a dominant role in the initial nucleation stage, while the multiple mechanisms, the various influences and the mastery reaction are easily affected by the external conditions. To obtain a more universal mechanistic insight on LDH formation and provide a theoretical basis for the prospective development of LDH, a general formation mechanism need to be clarified, which requires explanations from the conclusive building rules and difference of LDH laminate as well as the internal mechanism and scientific nature of the formation process in macro and micro perspectives.

Photocuring technology is highly efficient, adaptable, economical, energy-saving and environmentally friendly, making photocuring polymeric materials widely used in human production and life in recent years. However, the structural stability of Photocuring polymeric polymers makes it difficult to repair the materials once they are broken on the surface or inside, resulting in a large amount of wasted resources and environmental pollution. Dynamic covalent bonds can be reversibly broken and reorganized under the action of external stimuli (light, heating, etc.), which leads to dynamic adjustment of molecular topology and gives light-cured polymer materials structural adjustability, recyclability and self-healing properties. This paper reviewed the design and preparation of photocuring polymeric materials based on ester bonds, Diels-Alder reaction, disulfide bonds, borate ester bonds, site-resistant urea bonds and other reversible covalent bond self-repairs in recent years, summarized the advantages, disadvantages and applications of different types of dynamically covalently bonded photocuring polymeric materials in recent years, and finally pointed out the weaknesses of the mechanical properties of dynamically covalently bonded photocuring polymeric materials and the singularity of the former based on dynamically covalent bond repair, and gave an outlook on the future research directions in this field.

Modern coal gasification technology is an important part of modern coal chemical industrial plants,involving stable operation of the entire coal plant. This paper introduces application of modern coal gasification technologies in China,summarizes characteristics of gasification processes,application parameters,market data,etc. The first class gasification technology is entrained-bed gasification process,which can be divided into dry pulverized coal pressurized gasification and wet coal-water slurry pressurized gasification. The typical dry pulverized coal pressurized gasification technologies include Shell Gasifier,GSP Gasifier,HT-LZ Gasifier,WHG (Ning Mei) Gasifier,Two-stage Gasifier,CHOREN CCG Gasifier,SE Gasifier. The typical wet coal-water slurry pressurized gasification technologies include GE (Texaco) Gasifier,coal-water slurry gasifier with opposed multi-burners,Multi-component Slurry Gasifier,Non-slag/slag Gasifier (modified as Tsinghua Gasifier),E-gas (Destec) Gasifier. The second class gasification technology is fluidized-bed coal gasification process. The typical fluidized-bed coal gasification technologies include U-gas Gasifier,SES Lignite Gasifier,CAGG Gasifier. The third class gasification technology is fixed-bed coal gasification process. The typical fixed-bed coal gasification technologies include Lurgi Lignite Gasifier,Crushed coal Pressure Gasifier,BGL Gasifier. This paper points out the importance of coal gasification and recommends the strategic goal of combination of foreign advanced coal gasification concepts and modern coal gasification technologies with independent intellectual property rights.

Tungsten disulfide (WS₂), as a typical two-dimensional transition metal sulfide with a wide layer spacing (6.2Å，1Å=0.1nm) and a multi-electron conversion reaction sodium storage mechanism, is a sodium ion battery anode material with high theoretical specific capacity and fast sodium ion reaction kinetics. However, in its actual sodium storage process, the electronic conductivity inherent in the 2H phase structure of WS₂ is poor, and the large phase structure transformation and volume change are brought about by the conversion reaction, as well as the dissolution and shuttle effect of the reduced intermediate product polysulfide (NaS _x, 0<x<2) and the low conductivity of the reduced product sodium sulfide (NaS₂) during the charging and discharging process, leading to the less than ideal actual electrochemical performance of WS₂. To address the above problems, this paper introduced the basic structural features of WS₂, briefly described the main synthetic methods and modifications that existed, and researchers has used hydrothermal/solvent thermal and high-temperature sulfidation methods for nanostructure design, compounding with carbon materials, and introducing a second phase to build a heterogeneous structure to enhance the electrochemical performance of WS₂. Finally, the main modification methods of WS₂ materials and the achieved results are summarized. In the future research direction of WS₂ sodium storage materials, the combination of various modification strategies such as nanostructure design, compounding with carbon materials, constructing heterojunctions, doping with heterophase atoms and increasing active sites to fabricate high magnification performance WS₂ materials that can achieve fast charging and discharging with stable structure is the focus of research.

High-quality sulfur-containing chemicals is still widely used in industries. And some of them are even facing a short supplying. Reusing and further processing for hydrogen sulfide from waste gas are not only economical beneficial but also environmentally friendly. This paper discussed 16 kinds of sulfur-containing compounds,which are classified further in eight sorts: inorganic sulfide,thiol,thioether,thiophenol,thioamide,sulfur-containing heterocycles,organic bisulfide,and high valence sulfur-containing organics. The basic physical and chemical properties,the main applications,and the market supplying of those compounds were presented. The status of research on the main synthetic methods both domestic and abroad was discussed with a focuses mainly on the industrial synthesis routes and the other synthesis routes based on the raw material hydrogen sulfide to develop the downstream products from recycled hydrogen sulfide rationally,an overall consideration should be conducted among the factors such as market positioning,technical manners and resource integration. Based on the current market,the methionine,polyphenylene sulfide are having promising market,which may be the priority for the future research.

Biogas residue was a solid residue produced by anaerobic fermentation of biomass, which was also a secondary resource with great application potential. Compared with the traditional biogas residue treatment process such as landfill and incineration, the use of thermochemical method to treat waste biomass biogas residue could achieve the fixation of organic matter in the biogas residue, and the prepared biogas residue biochar had stable structure and excellent performance, which could be widely used in pollutant adsorption, catalytic degradation, soil remediation and many other fields. This paper summarized the common preparation technologies and modification methods of biogas residue biochar at home and abroad, and focused on the structure, elemental composition and physical and chemical properties of biogas residue biochar. At the same time, the main resource application ways of biogas residue biochar were summarized, and the development direction of biogas residue biochar resource utilization in the future was prospected.

CO₂ mineral curing technology is based on the carbonation reaction and product formation process between the early-formed concrete material and CO₂ to improve the mechanical strength of concrete products. The development of CO₂ mineral carbonation curing focuses on the mineralization reaction (i.e., accelerated carbonation) between the binder materials and CO₂ in the concrete after pre-curing/early hydration molding. In this process, the hydration process of the cementitious material is no longer the main reaction for the strength gain. Therefore, in order to fully realize the mineralization cementation and the CO₂ fixation, and maximize the environmental benefits, researchers have widely explored the alkali metal materials with CO₂ mineralization potential in recent years, and investigated the effect of mineralization reaction on the microstructure and properties of concrete. In this paper, the research progress of CO₂ mineral carbonation curing technology on novel concrete materials is reviewed. The hydraulic calcium silicate materials used in traditional concrete, non-hydraulic calcium silicate materials, magnesium-based cement materials and industrial solid waste materials are considered and compared. The paper introduced the latest achievements on the CO₂ reaction characteristics of different materials and the performance optimization of building materials after curing. The prospects for the future development of CO₂ mineral carbonation technology are also summarized. The main suggestions include: firstly, focusing on the microstructure reaction mechanism and mineral properties, and developing effective reaction enhancement methods; secondly, developing the non-hydraulic calcium silicate materials; thirdly, combining the industrial solid waste recycling and the CO₂ mineral carbonation processes to use solid waste and gas waste in one process, and developing the specific process and device.

Pickering emulsion refers to an emulsion that is stabilized by micro-nano solid particles instead of traditional surfactants as an emulsifier. It has strong stability and an ultra-high oil/water interface, which can provide an efficient and stable place for multi-phase interface reactions and mass transport. The structure of emulsion droplet and properties of Pickering emulsion depends on the size, morphology and surface properties of the solid particles. Pickering emulsions can be endowed with specific responsive functions via adjusting the properties of the solid particles or their surfaces, resulting in wide application fields. This paper reviewed the main research results of Pickering emulsions with different response types (magnetic, CO₂, pH, light, temperature and other response types), focusing on the stability principle of Pickering emulsions, the preparation methods and structural regulation of response Pickering emulsions, and the recent application research progress of Pickering emulsion in matter separation. Finally, the development trend of the application research of Pickering emulsion was prospected.

Magnesium based hydrogen storage materials have the advantages of high hydrogen storage capacity, low price, and abundant magnesium resources in nature, and thus are considered as the most promising solid hydrogen storage materials. Due to the good stability of MgH₂, the high enthalpy of hydrogen desorption (75kJ/mol H₂), the high dissociation energy of hydrogen molecules on the surface of Mg and the slow diffusion rate of hydrogen atoms in the magnesium lattice, the absorption and desorption of hydrogen are stable in thermodynamics but the kinetics is slow, which limits its application in hydrogen storage. Many research achievements have been made to improve the properties of magnesium based hydrogen storage materials and this paper reviews these research reports, and summarizes the modification methods with the focuses on the effects of alloying, nanocrystallization and catalyst addition on the optimization and improvement of the thermodynamic and kinetic properties, and the mechanism of hydrogen absorption and desorption. Finally, the development prospects in this field are prospected. Based on the existing analysis, it is concluded that catalyst addition and nano modification should be comprehensively used to regulate the thermodynamic properties of MgH₂ system in the future research obtain the Mg/MgH₂ hydrogen storage system with high capacity and high performance, which could meet the requirements of commercial applications.

Microreactor belongs to the miniature chemical reaction system, which has some characteristics of high heat-and mass-transfer rates, strictly-controlled reaction time, easy scale-up, excellent safety performance, and so on. Comparing with the common batch reactors, advantages of microreactors are reducing reaction time, greatly promoting conversion and yields. On the other hand, there are some existing challenges, such as the clogging problem, catalyst loading, design and fabrication of microchannels, and so on. This paper aims to introduce the microreactor technology, which has been growing rapidly in recent years. Some of the basic characteristics of microreactor are summarized focusing on applications of microreactor in chemistry and chemical engineering as well as some of typical examples of existing in fine chemical and pharmaceutical industry. A variety of challenges are also discussed. Microreactor is a frontier and hot topic in the research of chemistry and chemical engineering and analysis shows that microreactor still has very big development space and has the potential to change the chemistry and chemical engineering landscape. In the future, further in-depth and systematic understanding of the regularities and mechanisms of chemical reaction in microreactor and design of microchannels should be emphasized. Introducing the microreactor technology into more reaction systems and further improving the integration level still need to be perfected.

CO₂ can be converted into syngas via reverse water-gas shift (RWGS) reaction,followed by the F-T reaction to produce C_xH_y fuels or oxygenated chemicals,which have a significant impact on the environment and the energy structure of the future society and the catalyst plays a key role.The catalyst systems of RWGS reaction are reviewed,especially for the effect of interaction between metal and support,the preparation methods,and the electronic effect of doping elements on RWGS reaction performance of the corresponding catalyst are analyzed.Further,the application of Ce-based catalyst in RWGS reaction was discussed.Optimizing the active component can effectively improve the RWGS reaction performance of the corresponding catalysts for the hydrogenation reduction of CO₂ into syngas,and provide a foundation for the industrialization of RWGS reaction.The differences between noble metal and non-noble metal catalysts are also evaluated from points of the preparation methods,reaction conditions,and RWGS reaction performance.The development of novel catalyst material is the key to the industrial application of the RWGS reaction.

Fluidized bed-chemical vapor deposition (FB-CVD) is widely used in industrial production owing to the combined advantages of both fluidized bed and chemical vapor deposition. Providing good heat and mass transfer, it can obtain a pure product with uniform deposition. Based on its basic principle, the applications of FB-CVD in areas of particle coating, preparation of one-dimensional nano-materials, polycrystalline silicon, powder synthesis and powder surface modification are reviewed. The progress of process simulation and reactor structure design of FB-CVD is introduced. From the discussion, the scientific connotation of FB-CVD shows multi-scale features, namely material preparation at microscopic level, particle fluidization at mesoscopic level and reactor structure design at macroscopic level. Future development of FB-CVD technology depends on coupling analysis of these three scales, and research should be focused on the effect of interaction between different scales, such as coupling between homogeneous nucleation material/non-homogeneous nucleation in materials preparation and particle fluidization in the reactor.

Glass fiber reinforced resin is the most widely used engineering composite material. Since the end of the 20th century, more and more attention has been paid to the interface bonding between glass fiber and resin matrix. The nanocomposite coating called "sizing" on the surface of glass fiber contributes greatly to the smooth production and application of glass fiber. In addition, sizing serves as a crucial "chemical bridge" for the interface bonding or interaction between glass fiber and the resin matrix. However, the sizing formulations of giant glass fiber manufacturers are highly confidential, and the related industries also lack comprehensive or reliable database on the science and technology of glass fiber sizing, limiting the acquisition the sizing knowledge and effect in composite products for researchers. In this work, the characterization and analysis methods of glass fiber sizing agents were reviewed through extensive comparative analysis of published works, so as to help the R&D and production personnel in composite industry to better understand the role of glass fiber sizing in reinforced composites. In this work, the basic knowledge of glass fiber sizing was introduced first in brief. Then, some typical characterization and analytical methods of sizing were introduced. Finally, the current research status was summarized and the challenges of characterization technology were discussed and prospected.

Magnetorheological fluid is a type of smart material which exhibits fast(less than milliseconds),continuous,reversible changes in their rheological properties with low power requirement. These outstanding properties make them very promising for applications in machinery,automobile,precision machining,and active control engineering etc. Based on the latest research achievements,this paper reviewed the characteristic and application of magnetorheological fluid and discussed the problems that need to be resolved. The conceptual definition of magnetorheological fluid was conducted from the aspect of complex fluid,smart fluid,and structured fluid,respectively. Special emphasis is paid to the understanding of their magnetization,rheology,stability,redispersibility,and tribology performance of MRF. Finally,the future developments of magnetorheological fluid are also presented from the view of physical state and structural rheology.

Anode materials is one of the key factors for the commercialization of sodium-ion batteries (SIBs), and the related in-depth research in recent years has led to some breakthrough. However, the large radius of sodium-ion has a great impact on the battery performance. This article systematically reviews the new results of anode materials for SIBs in the preparation and performance characteristics, covering carbon-based materials, titanium-based compounds, alloy materials, metal compounds and organic compounds and the focus is on the structure-performance relationship. The key issues and strategies related to the research and development of SIBs anode materials are highlighted. In addition, the perspective and new directions of SIBs are briefly outlined. It is necessary to develop new modification methods to realize carbon coating, nanostructure, porous morphology and element doping in order to meet the requirements of different energy storage fields.

As a value-added chemical product derived from renewable biomass, the furfural has many promising applications. In this paper, recent advances in the furfural production from biomass via hydrolysis were summarized, and the important derivatives of furfural and their applications were discussed. Based on the mechanical analysis of hemicellulose hydrolysis reaction and xylose dehydration reaction, the production advances of furfural via hydrolysis were discussed from the aspects of feedstock, solvent system, catalyst, and separation process. Furthermore, the shortcomings and possible solutions of the current furfural production method were proposed. In addition, the synthesis of high value chemicals via the hydrogenation, amination, oxidation, acetal or polymerization of furfural was summarized. In order to realize the green and efficient production and application of furfural, the reaction system with low cost, low energy consumption, low pollution, and high efficiency should be designed. At the same time, it’s very important to develop an economic and environmentally-friendly method to achieve the complete utilization of furfural-derived products.

Molten metal methane pyrolysis is an emerging hydrogen production technology in recent years. Compared with conventional methane pyrolysis and catalytic pyrolysis, it effectively overcomes the problems of high energy consumption, low conversion and catalyst deactivation, and also avoids the high carbon emission as in steam methane reforming technology. The ability to produce value-added solid carbon products along with hydrogen has attracted extensive attention. This article summarizes the latest research and development of methane pyrolysis based on molten metal technology, focusing on the process flow, reaction mechanism, selection of molten medium and rector design etc. We also propose two types of potential reaction mechanisms for elucidating whether the liquid medium plays a catalytic role in methane pyrolysis. Moreover, the selection principle, trends in the development, benefits and drawbacks of different types of molten media are comprehensively elaborated. And the technical economy and greenhouse gas emission reduction also have been discussed, which further demonstrates the feasibility and potential benefits of the process. Finally, suggestions for future technological improvements are presented, and we points out morphology regulation of carbon materials to facilitate transformation into high-value-added products should inevitably become one of the key development directions in the future.

In this work, adsorption, activation, and reactivity of NH₃ and NO on the selective catalytic reduction （SCR） catalysts and the effects of H₂O and SO₂ on the reaction behaviors of NH₃ and NO were reviewed. The analysis shows that the co-reaction between the H-abstraction products of the adsorbed NH₃ and the adsorbed NO species (or gas phase NO) is the key to determine the NH₃ reactivity and the final SCR product. The gas phase NO could react with the H-abstraction products of the adsorbed NH₃ directly (Eley-Rideal mechanism). In addition, a lot of conversion products, such as nitrites and nitrates species, could form after NO was adsorbed and activated on the catalyst surface. These species could also react with adsorbed NH₃ species (Langmuir-Hinshelwood mechanism). This is another important pathway for NO to participate in the SCR reaction, especially at low temperature. It is beneficial for the adsorption and conversion of NH₃ and NO to enhance the catalyst acidity and redox ability. The effects of H₂O and SO₂ on the catalyst are influenced by the temperature. At high temperature, the effect of H₂O on the catalyst is very little, while the catalyst acidity could be enhanced by SO₂, which enhance NH₃ adsorption. At low temperature, however, the adsorption and conversion of NO could be inhibited severely by H₂O and SO₂, especially the SO₂. The accumulation of ammonia sulphate and the conversion of active sites to sulphate could result in severe deactivation of the catalyst. Therefore, it is still a severe challenge to improve the H₂O and SO₂ resistance ability for developing low temperature SCR catalyst. It is of great significance to increase the catalyst temperature to decompose the nitrate and sulfate to regenerate the catalyst in operation.

Hydrogen energy is one of the most promising energy carriers to support smart grid and large-scale of power generation by renewable energy. Water electrolysis is one of the most important routes to realize the large-scale of hydrogen production. Among the technologies of water electrolysis, proton exchange membrane electrolyzer (PEMEL) technology has attracted the attention of scientific and industrial communities because of its advantages of high current density, high purity of hydrogen production and fast response speed. This paper firstly introduces the structure of PEMEL and the main functions of each component. The technical differences between the alkaline electrolyzer, solid oxide electrolyzer and proton exchange membrane electrolyzer are compared and analyzed. Through explaining the mechanism of oxygen evolution reaction and hydrogen evolution reaction, this paper introduces common electrocatalysts for electrochemical water splitting. With the advantages of low cost and improved performance, non-noble metal catalysts are becoming more competitive. Then, from the initial laboratory research stage to the current megawatt-level PEMEL, this paper reviews the development process and application of the technology. Further, the current bottlenecks of the technology are discussed from multiple perspective. The major bottlenecks of PEMEL are the cost of hydrogen production, the performance of electrode material and the life of stacks. Finally, it is prospected based on the advantages of PEMEL that the application of such technology has a promising future for the renewable energy demand as well as the joint application with other industries.

As a new two-phase heat transfer technology, vapor chamber has the advantages of high thermal conductivity, good temperature uniformity, reversible heat flow direction, and so on. It overcomes the problems of traditional heat pipe, such as small contact area, large heat resistance and ununiform heat flow density, and has become one of the effective ways to solve the heat dissipation of electronic devices with high heat flow density in the future electronic industry. In this paper, the three types of wick structures, namely, grooved, sintered powder and sintered wire mesh were summarized, and the preparation methods of each capillary wicks were introduced and their advantages and disadvantages were compared. The latest research progress of heat and mass transfer theory in vapor chamber was reviewed. the boiling theory of transport model to capture the gas-liquid interface was used by researchers. The critical heat flux was confirmed. The flow and heat transfer law of working medium was analyzed in the vapor chamber. Then, the factors affecting the performance of vapor chamber, including fluid selection, liquid filling rate, heat load, inclination, et al. were analyzed. Finally, the application direction of the vapor chamber was prospected from the perspective of background environment.

Phosphine is widely produced from paddy cultivation, refuse landfill, wastewater treatment, industrial production or other sources. However the formation mechanism and transformation pathway of phosphine in the environment are still unclear. Based on the environmental benefits of phosphine, this review investigated the release and spatiotemporal distribution of two kinds of phosphine, free gaseous PH₃ and matrix-bound PH₃, and analyzed the transformation pathways including catalytic conversion, photochemical oxidation, microbial degradation and so on, then explored the mechanism for PH₃ conversion and analyzed some significant problems related to the biogeochemical cycling of phosphine. According to the obtained research on source and sink analysis as well as phosphine’s transport and transformation in environment, follow-up research can focus on the following three aspects: ① the formation mechanism and process intensification of gaseous phosphine in the anaerobic wastewater treatment system; ② the response relationship between water eutrophication and phosphine and its oxidation products; ③ the mechanism and specific pathway of phosphine bio-oxidation system.

Metal organic framework (MOF) is a new type of porous material with high specific surface area, abundant active sites and easy chemical modification. However, its poor water stability limits its application in adsorption of volatile organic compounds (VOCs). Therefore, one hot topic of MOF research is to improve its VOCs adsorption performance. This article reviews the research progress of MOF and its composites for the removal of VOCs from the aspects of synthesis of monomeric MOF, the preparation of MOF composites, the adsorption mechanism and the influence factors in adsorption. In view of the shortcomings of MOF materials in the adsorption of VOCs, research suggestions are put forward. The development directions of MOF materials in VOCs adsorption are to prepare new MOF materials with rich micro-mesoporous structure and active sites, strong hydrothermal stability, good resistance to water vapor’s competition adsorption and high recycling utilization, and to develop new synthesis methods.

Microencapsulation of essential/fish oil can improve its inoxidizability, stability, bioactivity and awful smell. Chitosan and its derivatives are good wall materials due to their biocompatibility, film forming ability and permeability on microencapsulation of essential/fish oil. Microencapsulation technology of essential/fish oil is reviewed in this paper, according to the main line of chitosan-based wall materials and combining different microencapsulation mechanisms. The advantages and disadvantages of different kinds of chitosan wall materials (plain chitosan, chitosan complex and chitosan derivatives) and microencapsulation methods (spray-drying, single coacervation, emulsion cross-linking and layer by layer self-assembly) are discussed. In the future, they are considered as an important research area, for example improving microencapsulation methods in order to control particle size and increase oil embedding rate and developing nontoxic and efficient membrane crosslinkers in order to control the release efficiency of essential/fish oil. In addition, it is also important to prepare new wall materials of chitosan derivatives for increasing the functional properties of essential/fish oil microcapsules.

With the development of processing technology and the emergence of new material, the excellent properties of micro-channel heat exchanger are paid great attention by people gradually.Hence the micro-channel heat exchanger is rapidly expanded into different areas, for example, aerospace engineering, HVAC, MNSR, fuel cell power submarine, etc.But there are some problems in the research and application of micro-channel heat exchanger, which limit its popularization, such as the mechanism and numerical calculation of the two-phase flow heat exchange, the distribution of refrigerant and air flow in HVAC, frosting problem in heat pump system, industry specifications of manufacture, etc.Therefore, around the above problems, this paper, in order to provide the reference for the researchers, introduces the technical characteristics of micro-channel heat exchanger by comparing with other types of heat exchangers, summarizes the research status and the application field of micro-channel heat exchanger mainly by the research results at home and abroad in recent years and points out the application prospect and the research direction in the future.

The development status of hydrogen production technology from coal, natural gas, methanol and hydrogen recovery from industrial byproducts was analyzed in detail. The production cost and economy of several hydrogen production technologies from fossil raw materials were studied and compared, and the development prospect of hydrogen production technology from fossil raw materials was deeply considered. The conclusion was that coal hydrogen production technology had excellent resources. Coal-based hydrogen production was the preferred technology for large-scale hydrogen production because of its potential and cost advantages. Natural gas-based hydrogen production had great development potential, but there were problems of resource constraints and high cost. By-product hydrogen recovery was a potential hydrogen production mode in the future. Methanol-based hydrogen production was flexible in scale, but it had shortcomings of high equipment cost and poor stability. Under the current situation that new energy hydrogen production technologies such as solar energy were not yet mature, hydrogen production from fossil raw materials will play a major role. In the future, hydrogen industry will be the supply pattern of coexistence and diversified development of various ways of hydrogen production from fossil raw materials， electrolytic water and new energy.

The emerging carbon-negative technologies like direct air capture (DAC) guarantee the carbon neutral and therefore receive growing attention. In this study, the characteristics of DAC are briefly analyzed. Amine-functionalized inorganic materials, polymers, metal hydroxides and carbonates are compared and reviewed in terms of trace carbon dioxide capture performance. And the relationship between adsorption capacity and kinetics with loading methods, and hierarchy texture of support are clarified. Finally, the challenges in this field and the suggestions from the point of energy-consuming and capture efficiency are put forward. Firstly, amine functionalized materials and solid base sorbent display better potential in practical application than physisorption materials. Secondly, integration and use of the existed deep removal processes as references could develop and optimize the process. At last, facing the sever environmental problems, the development of the new material and low energy-consuming regeneration method should be concentrated in the future.

Polyaniline is the famous conjugated polymer that used widely in rechargeable batteries shielding of electromagnetic interference, microwave and radar absorbing materials, non-linear optical and light-emitting devices, fuel and solar cells.The method of synthesis is devoloping and the mechanism of synthesis is devoloping also.The paper reviews the new research result about the synthesis and mechanism from 2013 to 2015, especially the azo benzene polymer that use dianiline as raw material.The polymer show good conductive capacity after dosing, will be used wildly in rechargeable batteries shielding of electromagnetic interference, microwave and radar absorbing materials, non-linear optical and light-emitting devices, fuel and solar cells.The synthesis mechanism is clear, simple synthesis process, is worth to study further.

The materials and technologies of electrochemical energy storage are essential for the utilization of new energy and the achievements of carbon peaking and carbon neutralization. Based on the research work of Shanghai Key Laboratory of Materials Protection and Advanced Materials in Shanghai University of Electric Power, various electrochemical energy storage technologies are comprehensively reviewed in this paper, including lithium-ion batteries, sodium-ion batteries, lithium-sulphur batteries, and supercapacitors. The current problems of electrochemical energy storage technologies are also analyzed. From the perspective of electrochemical energy storage mechanism, the modification methods of cathode, anode, separator, and current collector materials are introduced. These methods provide new ideas for the development of electrochemical energy storage devices with large capacity, long life, high safety and low cost. At last, future development trends of electrochemical energy storage technologies are proposed, including exploring new generation energy storage devices such as all-solid-state batteries and metal-air batteries and expanding the application of electrochemical energy storage devices under wide temperature and flexible conditions.

Oily wastewater is generated in many industrial processes, such as petroleum refining, petrochemicals, food, leather and metal processing, and has always been the focus of industrial pollution control. With the continuous development of industrial production technology, the types of characteristic pollutants in oil-containing wastewater and their discharges have also continued to increase, posing challenges to the deep removal and recovery of oil from industrial wastewater. Due to the variety of organic matters in the oily wastewater, the different environments, and the complex internal reactions, it not only affects the production efficiency of the multi-stage process, but also has an environmental risk. Therefore, the efficient and advanced treatment and utilization of industrial oily wastewater is an inevitable requirement for industrial pollution control, and has an important role in promoting the sustainable development of industrial production. In view of this, on the basis of systematic analysis of the characteristics of industrial oily wastewater, this article reviews the latest research progress at home and abroad on the treatment of emulsified oil and dissolved oil from the perspective of separate processes and combined processes, and focuses on principle and characteristics, degreasing potential, application benefits and its advantages compared with the other degreasing technologies. Finally, the perspective for resin degreasing technologies is presented.

The devolatilization process follows different heat and mass transfer mechanisms due to different volatile contents in polymers. It is of great significance to develop efficient devolatilization technology and equipment based on its determining mechanism. In this paper, different theories, models and characteristics of three consecutive stages of polymer devolatilization process, namely, flash-devolatilization, foam-devolatilization and diffusion-controlled-devolatilization, have been systematically introduced. The intensification methods of devolatilization process have also been reviewed in both engineering and technology perspectives. Correspondingly, new technologies, such as grid falling film reactor, higee, supercritical fluid assistance and ultrasonic enhancement, and their applications were described in detail. Future research directions of polymer devolatilization theory and engineering practice were proposed as following: the coupling mechanism between diffusion-controlled-devolatilization and foam-devolatilization needs to be studied further to establish more precise and universal devolatilization mechanisms; and the grid falling film devolatilization technology is prospective in mass-scale industrial devolatilization process due to its energy efficiency advantages.

Hydrogen energy is an important development direction of the global energy technology revolution. In the development process of the hydrogen energy industry, the development of efficient, safe and low-cost hydrogen energy storage technology is the necessary guarantee and key to the realization of large-scale hydrogen consumption. This paper reviews four current mainstream hydrogen energy storage technologies——high-pressure gaseous hydrogen storage, low-temperature liquid hydrogen storage, liquid organic hydrogen storage, and solid material hydrogen storage, analyzes and sorts out the advantages and disadvantages of these hydrogen storage technologies, discusses the latest research status and key challenges of various hydrogen storage methods, and prospects the optimization and development trend of hydrogen storage technology in the future. It can be found that in order to improve hydrogen storage, researchers focus on developing cost-effective, energy-dense hydrogen storage technologies. It is suggested that high-pressure gaseous hydrogen storage should focus on the development of low-cost, high-performance carbon fiber composite materials to reduce the cost of type Ⅳ bottles; low-temperature liquid hydrogen storage should focus on reducing hydraulic costs and seeking cheap and readily available thermal insulation materials; for liquid organic hydrogen storage, seeking high-efficiency catalysts can greatly improve its hydrogen storage capacity; and solid material hydrogen storage should develop high-efficiency catalysts and seek ways to improve the interaction between hydrogen and materials. The government, enterprises and scientific research institutes should vigorously promote the research on hydrogen storage technology, accelerate the development of the hydrogen energy industry, and realize the goal of carbon neutrality as soon as possible.

With the rapid development of Chinese economy,the fossil fuel consumption,such as coal,petroleum,etc.,is increasing continually so that the haze appears frequently and the areas of acid rain continue to expand. A large amount of sulfur dioxide emissions have led to the current situation that the pressure on the environment has intensified. This paper briefly introduces the technologies of dry,semi dry and wet flue gas desulfurization and their advantages and disadvantages. Advantages and disadvantages of different wet flue gas desulfurization methods,such as limestone-gypsum method,sodium alkali method,ammonia method,magnesium method,organic amine method,sea water method,phosphate rock slurry method were discussed. The main aim of this paper is to elaborate the new phosphate rock slurry method and its desulfurization mechanism as well as comparing the characteristics and application range of different wet desulphurization technologies. Through economic analysis of phosphate rock slurry and sodium alkali method,limestone-gypsum and magnesium method wet flue gas desulfurization technology,the running cost of phosphate rock slurry wet flue gas desulfurization technology is the lowest among those technologies. The recovery of sulfur dioxide becomes sulfuric acid by catalytic oxidation,getting into phosphorus chemical industry chain and replacing some of the sulfuric acid. The method has no by-products and no secondary pollution and is suitable for enterprises and parks with phosphate rock production. The principle of phosphate rock slurry wet flue gas desulfurization technology can be extended to the wet metallurgical enterprises.

In order to avoid the negative impact of greenhouse effect, the reduction of CO₂ emissions has become an urgent task. As a potential CO₂ emission reduction technology, CO₂ mineral carbonation has attracted extensive attention. CO₂ mineral carbonation methods mainly include the direct dry carbonation route, direct aqueous carbonation route, and indirect carbonation route. At present, the key challenge in CO₂ direct or indirect carbonation methods is to improve the kinetic characteristics of CO₂ carbonation. The slow reaction rate and low carbonation efficiency are the main problems of the current technology. The traditional CO₂ amine chemical absorption method has the advantages of fast absorption rate, large absorption capacity, and absorbent recycling, but the energy consumption and operating cost are high. The integrated CO₂ absorption-mineralization technology (IAM) developed by the combination of the CO₂ amine chemical absorption and CO₂ carbonation process not only solves the problems of high energy consumption and low conversion rate of the traditional process but also simplifies the process flow and reduces the cost, which is beneficial to industrialization. This paper summarizes the research progress of CO₂ mineralization technology in recent years and compares the different characteristics of various technological routes. It points out that strengthening the research on the reaction mechanism of the IAM process and the development of efficient and economical absorbent and mineralized raw materials are the key of the future research of this process.

Anaerobic ammonium oxidation(Anammox)has advantages of high efficiency and low consumption. This method has become a promising biological nitrogen elimination process. This paper compared the operation conditions of one-and two-stage Anammox processes,analyzed the habitat and species diversity of anaerobic ammonium oxidizing bacteria and process versatility of Anammox,and summarized the laboratory research and engineering applications of Anammox in the treatment of various types of ammonium-rich wastewater. The characteristics,research progress and application barriers of sludge digestate,reject water,landfill leachate,livestock wastewater, municipal sewage,saline wastewater etc were introduced. Moreover,the potential problems of Anammox process in practical applications were discussed and further research focuses were suggested.

With the acceleration of industrialization, the types and discharge of wastewater are increasing, which has caused serious harm to the natural environment and human society. Therefore, it is urgent to develop economical and efficient wastewater treatment technology. Bio-electro-Fenton (BEF) system is a water treatment technology which combines bioelectrochemical system with Fenton oxidation process. As a high efficiency, green and energy saving approach, BEF system is attracting a growing interest recently. Here, the work principle of BEF system was introduced. Main factors influencing the properties of anode and cathode were discussed, including the extracellular electron transport process of microorganisms, anode materials, cathode materials, catalysts of Fenton reaction and system operating conditions. The application of BEF system in various wastewater (dye wastewater, pharmaceutical wastewater, landfill leachate, coal chemical wastewater and swine wastewater) treatment was summarized. Finally, the current challenges and future research directions of BEF system were pointed out, including developing the efficient electrode materials and catalysts, coupling with other water treatment processes, reducing the cost of membrane materials and conducting pilot studies, in order to support its further development.

Plastics play an important role in social and economic development, while their mass production and inappropriate disposal have caused serious ecological disasters. The transformation of waste plastics into value-added products through chemical recycling and upcycling is one of the key technologies to achieve sustainable development of plastic resources. This review comprehensively summarizes recent progress in waste plastic valorization by various methods (e.?g., catalytic pyrolysis, solvolysis, hydrogenolysis, photocatalysis, chemical oxidation, etc.), focusing on discussing the effects of reaction conditions on product distribution and yields, structure-activity relationships, and reaction mechanisms. In view of the existing problems such as harsh reaction conditions, high catalyst cost and low reuse ability, future research directions are proposed, including optimization of process conditions, clarification of catalyst deactivation mechanism and development of inexpensive and efficient catalysts, which are expected to realize the industrial development of plastic resource utilization.