Abstract:

Monolithic catalysts are widely applied in various fields, and exploration on preparation methods for monolithic catalysts is critical for industrial applications. A series of Mn-Co monolithic catalysts of Mn/Co with different molar ratios immobilized on carbon fiber cloth substrate were prepared by electrodeposition method, and their NO oxidation activities were evaluated. Raman, XRD, SEM and other techniques were used to characterize the catalysts. The results showed that the Mn-Co binary catalyst prepared by electrodeposition method had a smaller particle size than cobalt oxide or manganese oxide unary catalyst by same method, and the minimum particle size was 3—4nm. Different Mn/Co molar ratios affected the catalyst particle size and phases a lot. The main substance after calcination of the catalyst with the highest manganese content was Mn₃O₄. With the cobalt content increasing, the main phase changed to Co₃O₄, but when Mn/Co=2, the phase of the catalyst was (CoMn)(CoMn)₂O₄. Co/Mn-based catalysts prepared by electrodeposition had much better NO catalytic activity than manganese oxide catalyst prepared by same method, its conversion was closed to 100% at 50℃.

Key words: catalyst, electrochemistry, composites, monolith, nanomaterials

摘要：

整体式催化剂性能高效、应用广泛，而制备方法是影响其性能的关键因素，因此探究简单高效的制备方法对整体式催化剂的工业应用至关重要。本研究以碳纤维布为载体，采用电沉积方法制备了一系列钴锰整体式催化剂，在固定床反应装置上考察了其催化氧化NO性能，并借助拉曼光谱仪、X射线衍射仪和扫描电镜等分析技术对催化剂进行表征。结果表明，采用电沉积法制备的钴锰二元催化剂比相同方法制备的氧化钴或氧化锰一元催化剂的粒径小，且钴锰比例对催化剂粒径影响很大，最小粒径为3～4nm。不同摩尔比例的钴锰二元催化剂焙烧之后物相差别较大，Mn/Co较高的催化剂的主要组成为Mn₃O₄，Mn/Co较低则趋向Co₃O₄，其中Mn/Co=2时，催化剂为(CoMn)(CoMn)₂O₄。电沉积法制备的钴锰整体式催化剂催化氧化NO的性能要远优于相同方法制备的氧化锰催化剂,在50℃下转化率均接近100%。

关键词: 催化剂, 电化学, 复合材料, 整体器件, 纳米材料