Bimetallic CoNi single atoms supported on three-dimensionally ordered mesoporous chromia:highly active catalysts for n-hexane combustion  

作　　者：Xiuqing Hao Yuxi Liu Jiguang Deng Lin Jing Jia Wang Wenbo Pei Hongxing Dai 

机构地区：[1]Beijing Key Laboratory for Green Catalysis and Separation,Key Laboratory of Beijing on Regional Air Pollution Control,Key Laboratory of Advanced Functional Materials,Education Ministry of China,Laboratory of Catalysis Chemistry and Nanoscience,Department of Chemical Engineering,Faculty of Environment and Life,Beijing University of Technology,Beijing,100124,China

出　　处：《Green Energy & Environment》2024年第7期1122-1137,共16页绿色能源与环境（英文版）

基　　金：supported by the National Natural Science Committee of China-Liaoning Provincial People's Government Joint Fund(U1908204);National Natural Science Foundation of China(21876006,21976009,and 21961160743);Foundation on the Creative Research Team Construction Promotion Project of Beijing Municipal Institutions(IDHT20190503);Natural Science Foundation of Beijing Municipal Commission of Education(KM201710005004);Development Program for the Youth Outstanding-Notch Talent of Beijing Municipal Commission of Education(CIT&TCD201904019)。

摘　　要：Developing the alternative supported noble metal catalysts with low cost,high catalytic efficiency,and good resistance toward carbon dioxide and water vapor is critically demanded for the oxidative removal of volatile organic compounds(VOCs).In this work,we prepared the mesoporous chromia-supported bimetallic Co and Ni single-atom(Co_(1)Ni_(1)/meso-Cr_(2)O_(3))and bimetallic Co and Ni nanoparticle(Co_(NP)Ni_(NP)/mesoCr_(2)O_(3))catalysts adopting the one-pot polyvinyl pyrrolidone(PVP)-and polyvinyl alcohol(PVA)-protecting approaches,respectively.The results indicate that the Co_(1)Ni_(1)/meso-Cr_(2)O_(3)catalyst exhibited the best catalytic activity for n-hexane(C_(6)H_(14))combustion(T_(50%)and T_(90%)were 239 and 263℃ at a space velocity of 40,000 mL g^(-1)h^(-1);apparent activation energy and specific reaction rate at 260℃ were 54.7 kJ mol^(-1)and 4.3×10^(-7)mol g^(-1)_(cat)s^(-1),respectively),which was associated with its higher(Cr^(5+)+Cr^(6+))amount,large n-hexane adsorption capacity,and good lattice oxygen mobility that could enhance the deep oxidation of n-hexane,in which Ni_(1) was beneficial for the enhancements in surface lattice oxygen mobility and low-temperature reducibility,while Co_(1) preferred to generate higher contents of the high-valence states of chromium and surface oxygen species as well as adsorption and activation of n-hexane.n-Hexane combustion takes place via the Mars van Krevelen(MvK)mechanism,and its reaction pathways are as follows:n-hexane→olefins or 3-hexyl hydroperoxide→3-hexanone,2-hexanone or 2,5-dimethyltetrahydrofuran→2-methyloxirane or 2-ethyl-oxetane→acrylic acid→CO_x→CO_(2)and H_(2)O.

关 键 词：Three-dimensional ordered mesoporous chromium oxide Supported bimetallic single-atom catalyst Cobalt-nickel single atoms n-Hexane combustion Catalytic reaction mechanism 

分 类 号：TQ426[化学工程] X701[环境科学与工程—环境工程]