无定形MnOx/SiO2催化剂的合成及低温催化氧化甲醛机理

doi:10.16085/j.issn.1000-6613.2019-0479

摘要/Abstract

摘要：

甲醛因其污染范围广、持续时间长、危害性大等特性被视为室内有害物质的头号“杀手”。本文采用自组装法于SiO₂表面原位生长MnO_x（MnO_x/SiO₂催化剂）并用于低温催化氧化甲醛的研究，XRD、SEM-EDS、TEM和BET表征显示，MnO_x以无定形态均匀地分布在SiO₂载体表面，同时考察了MnO_x的负载量以及煅烧温度对甲醛催化活性的影响。实验结果表明，优选的质量分数13% MnO_x/SiO₂无定形催化剂具有较大的比表面积（高达164.85m²/g）和丰富的活性位点（Mn³⁺，75.6%），而较大的比表面积有利于更多的甲醛分子吸附在催化剂表面并进行活化反应。对甲醛进行连续性动态检测，结果显示催化剂在连续催化6h后仍保持80%以上的去除效率，表明无定形催化剂具有良好的低温催化效果。随着温度的升高，催化甲醛过程中间产物（甲酸根）被进一步分解，有利于催化剂的再生使用，当温度达到90℃时，甲醛的去除效果可达90%。

关键词: MnO_x/SiO₂, 甲醛, 低温, 催化, 氧化, 化学过程

Abstract:

Formaldehyde is regarded as the world’s No.1 indoor hazardous substances because of its wide pollution range, long enduring time and great harm. In this paper, a self-assembly method to fabricate MnO_x (MnO_x/SiO₂ catalyst) onto the surface of SiO₂ is presented, and then the catalyst was used for the catalytic oxidation of formaldehyde at low temperature. XRD, SEM-EDS, TEM and BET measurements have shown that the MnO_x had an amorphous structure and were evenly distributed on the surface of SiO₂. The effects of the MnO_x dosage and calcinating temperature on the activity of the catalysts were evaluated. The optimization results showed that the amorphous catalyst of the 13% MnO_x/SiO₂ have a higher specific surface area (164.85m²/g) with many active sites（Mn³⁺, 75.6%）, which was beneficial for the adsorption and activation of formaldehyde. Continuous tests showed that the catalyst was able to maintain over 80% removal efficiency after 6 hours, which confirmed the good low-temperature catalytic activity of the amorphous catalyst. Moreover, the formate species on the catalyst can decompose at high temperature, which realizes the regeneration of catalyst. The formaldehyde removal efficiency was up to 90% when temperature reached 90℃.

Key words: MnO_x/SiO₂, formaldehyde, low temperature, catalysis, oxidation, chemical processes

中图分类号:

X511

朱荣辉,高凤雨,唐晓宁,郭洋洋,李阳. 无定形MnO_x/SiO₂催化剂的合成及低温催化氧化甲醛机理[J]. 化工进展, 2019, 38(12): 5402-5409.

Ronghui ZHU,Fengyu GAO,Xiaoning TANG,Yangyang GUO,Yang LI. Synthesis of amorphous MnO_x/SiO₂ catalyst and the mechanismfor low-temperature catalytic oxidation of formaldehyde[J]. Chemical Industry and Engineering Progress, 2019, 38(12): 5402-5409.

图/表 13

图1 动态实验装置流程

图2 MnOx/SiO2催化剂能谱图（EDS）、扫描电镜图及Si和Mn的面扫图

图3 MnOx/SiO2催化剂的XRD图和催化剂不同放大倍数下的TEM

图4 三种不同焙烧温度下催化剂的甲醛去除率对比

图5 负载型MnOx/ SiO2催化剂Mn基2p轨道XPS谱图和负载型MnOx/ SiO2催化剂H2-TPR谱图

表1 负载型MnOx/SiO2催化剂的XPS分析

样品	[Mn³⁺/(Mn⁴⁺+Mn³⁺)]/%	结合能/eV
200℃焙烧	73.66	641.55
250℃焙烧	75.55	641.83
300℃焙烧	70.64	641.64

图6 焙烧时间对甲醛去除效果（催化时间2h）

图7 不同Mn负载量对甲醛去除效果（催化时间2h）

表2 不同Mn负载量MnOx/SiO2催化剂的比表面积、 ICP分析

样品	Mn负载量（质量分数）/%	比表面积 /m²·g^-1	孔体积 /cm³·g^-1	平均孔径 /nm
MnO_x/SiO₂7%	6.32	128.34	0.94	30.96
MnO_x/SiO₂10%	9.12	163.10	0.97	24.69
MnO_x/SiO₂13%	11.86	164.84	0.97	23.83
MnO_x/SiO₂16%	14.93	152.93	0.92	24.63
MnO_x/SiO₂19%	17.84	140.79	0.83	24.22

图8 MnOx/SiO2催化剂升温甲醛去除效果和常温下连续性实验

图9 室温下甲醛混合气体在无定形MnOx/SiO2催化剂上的原位DRIFTS谱图

图10 不同温度下甲醛混合气体在无定形MnOx/SiO2催化剂上的原位DRIFTS谱

图11 无定形MnOx/SiO2催化剂表面甲醛吸附催化反应机理

参考文献 27

1	COLLINS J J, NESS R, TYL R W, et al. A review of adverse pregnancy outcomes and formaldehyde exposure in human and animal studies[J]. Regulatory Toxicology and Pharmacology, 2001, 34(1): 17-34.
2	李华亮, 李丽, 熊德甫, 等. 某企业办公室内空气质量及其健康风险评估[J]. 环境与职业医学, 2015, 32(3): 240-243.
	LI Hualiang, LI Li, XIONG Depu, et al. Assessment on indoor air quality in offices of a corporation and related human health risk[J]. Journal of Environmental & Occupational Medicine, 2015, 32(3): 240-243.
3	ZHAI L, ZHAO J, XU B, et al. Influence of indoor formaldehyde pollution on respiratory system health in the urban area of Shenyang, China[J]. African Health Sciences, 2013, 13(1): 137-143.
4	COLE P, ADAMI H O, TRICHOPOULOS D, et al. Formaldehyde and lymphohematopoietic cancers: a review of two recent studies[J]. Regulatory Toxicology and Pharmacology, 2010, 58(2): 161-166.
5	WOLKOFF P, NIELSEN G D. Non-cancer effects of formaldehyde and relevance for setting an indoor air guideline[J]. Environment International, 2010, 36(7): 788-799.
6	张淑娟, 黄耀棠. 利用植物净化室内甲醛污染的研究进展[J]. 生态环境学报, 2010, 19(12): 3006-3013.
	ZHANG Shujuan, HUANG Yaotang. Research progress on the elimination of indoor formaldehyde pollution by plants[J]. Ecology and Environmental Sciences, 2010, 19(12): 3006-3013.
7	ZHU X, GAO X, QIN R, et al. Plasma-catalytic removal of formaldehyde over Cu-Ce catalysts in a dielectric barrier discharge reactor[J]. Applied Catalysis B: Environmental, 2015, 170(1): 293-300.
8	YU J, WANG S, LOW J, et al. Enhanced photocatalytic performance of direct Z-scheme g-C₃N₄-TiO₂ photocatalysts for the decomposition of formaldehyde in air[J]. Physical Chemistry Chemical Physics, 2013, 15(39): 16883-16890.
9	KIBANOVA D, SLEIMAN M, CERVINI-SILVA J, et al. Adsorption and photocatalytic oxidation of formaldehyde on a clay-TiO₂ composite[J]. Journal of Hazardous Materials, 2012, 211(12): 233-239.
10	EWLAD-AHMED A M, MORRIS M A, PATWARDHAN S V, et al. Removal of formaldehyde from air using functionalized silica supports[J]. Environmental Science & Technology, 2012, 46(24): 13354-13360.
11	金晓东, 陈志坤, 曾利辉, 等.甲醛催化氧化技术与其他净化技术的比较[J]. 工业催化, 2018, 26(7): 6-10.
	JING Xiaodong, CHENG Zhikun, ZENG Lihui, et al. Comparison of formaldehyde catalytic oxidation with other purification technologies[J]. Industrial Catalysis, 2018, 26(7): 6-10.
12	BAI B, QIAO Q, LI J, et al. Progress in research on catalysts for catalytic oxidation of formaldehyde[J]. Chinese Journal of Catalysis, 2016, 37(1): 102-122.
13	HUANG H, LEUNG D Y C. Complete elimination of indoor formaldehyde over supported Pt catalysts with extremely low Pt content at ambient temperature[J]. Journal of Catalysis, 2011, 280(1): 60-67.
14	JIA M, SHEN Y, LI C, et al. Effect of supports on the gold catalyst activity for catalytic combustion of CO and HCHO[J]. Catalysis Letters, 2005, 99(3/4): 235-239.
15	TANG X, CHEN J, HUANG X, et al. Pt/MnO_x-CeO₂ catalysts for the complete oxidation of formaldehyde at ambient temperature[J]. Applied Catalysis B: Environmental, 2008, 81(1/2): 115-121.
16	SEKINE Y. Oxidative decomposition of formaldehyde by metal oxides at room temperature[J]. Atmospheric Environment, 2002, 36(35): 5543-5547.
17	TANG X, LI Y, HUANG X, et al. MnO_x-CeO₂ mixed oxide catalysts for complete oxidation of formaldehyde: effect of preparation method and calcination temperature[J]. Applied Catalysis B：Environmental, 2006, 62(3/4):265-273.
18	周祖卫, 余倩, 郝志峰, 等. 无纺布负载锰氧化物的制备及其催化分解甲醛性能研究[J]. 广东工业大学学报, 2018, 35(2): 6-10.
	ZHOU Zuwei, YU Qian, HAO Zhifeng, et al. Preparation of manganese oxide supported on non-woven fabric and its catalytic performance for formaldehyde decomposition[J]. Journal of Guangdong University of Technology, 2018, 35(2): 6-10.
19	公共场所空气中甲醛测定方法:GB/T 18204.26—2000：[S].
	Methods for determination of formaldehyde in the air of public places:GB/T 18204.26—2000[S].
20	MIRZAEI A A, FAIZI M, HABIBPOUR R. Effect of preparation conditions on the catalytic performance of cobalt manganese oxide catalysts for conversion of synthesis gas to light olefins[J]. Applied Catalysis A: General, 2006, 306(7): 98-107.
21	MIRZAEI A A, SHAHRIARI S, ARSALANFAR M. Effect of preparation conditions on the catalytic performance of Co/Ni catalysts for CO hydrogenation[J]. Journal of Natural Gas Science and Engineering, 2011, 3(4): 537-546.
22	刘育松, 高凤雨, 唐晓龙, 等. 制备条件对锰氧化物SCR脱硝性能的影响[J]. 环境工程学报, 2016, 10(1): 295-300.
	LIU Yusong, GAO Fengyu, TANG Xiaolong, et al. Effects of preparation conditions on selective catalytic reduction of NO by NH₃ over MnO_x catalyst[J]. Journal of Environmental Engineering, 2016, 10(1): 295-300.
23	LI J, ZHAO P, LIU S. SnO_x-MnO_x-TiO₂ catalysts with high resistance to chlorine poisoning for low-temperature chlorobenzene oxidation[J]. Applied Catalysis A: General, 2014, 482(7): 363-369.
24	周昕彦,张芃,蒋文,等.锰氧化物改性活性炭去除空气中甲醛[J]. 环境工程学报, 2015, 9(12): 5965-5972.
	ZHOU Xinyan, ZHANG Fan, JIANG Wen, et al. MnO_x/GAC for removal of formaldehyde in air[J]. Journal of Environmental Engineering, 2015, 9(12): 5965-5972.
25	KANG Min, PARK Eun Duck, KIM Ji Man, et al. Manganese oxide catalysts for NO_x reduction with NH₃ at low temperatures[J]. Applied Catalysis A: General, 2007, 327(2): 261-269.
26	YUNBING H E, HONGBING J I. In-situ DRIFTS study on catalytic oxidation of formaldehyde over Pt/TiO₂ under mild conditions[J]. Chinese Journal of Catalysis, 2010, 31(2): 171-175.
27	RACIULETE M, AFANASIEV P. Manganese-containing VOC oxidation catalysts prepared in molten salts[J]. Applied Catalysis A: General, 2009, 368(1/2): 79-86.

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无定形MnO_x/SiO₂催化剂的合成及低温催化氧化甲醛机理

Synthesis of amorphous MnO_x/SiO₂ catalyst and the mechanismfor low-temperature catalytic oxidation of formaldehyde

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