Catalytic oxidation of CO over Pt/Fe3O4 catalysts:Tuning O2 activation and CO adsorption  

作　　者：Zihao Li Yang Geng Lei Ma Xiaoyin Chen Junhua Li Huazhen Chang Johannes W.Schwank 

机构地区：[1]Department of Chemical Engineering,University of Michigan,Ann Arbor,MI 48109,USA [2]School of Environmental Science and Engineering,Shanghai Jiao Tong University,Shanghai 200240,China [3]School of Environment,Tsinghua University,Beijing 100084,China [4]School of Environment and Natural Resources,Renmin University of China,Beijing 100872,China

出　　处：《Frontiers of Environmental Science & Engineering》2020年第4期115-123,共9页环境科学与工程前沿（英文）

基　　金：This work was financially supported by the National Key Research and Development Program of China(Nos.2017YFC021100 and 2017YFC0210701);National Natural Science Foundation of China(Grant No.21936005);National Engineering Laboratory for Mobile Source Emission Control Technology(No.NELMS2018A12).

摘　　要：The self-inhibition behavior due to CO poisoning on Pt metal particles strongly impairs the performance of CO oxidation.It is an effective method to use reducible metal oxides for supporting Pt metal particles to avoid self-inhibition and to improve catalytic performance.In this work,we used in situ reductions of chloroplatinic acid on commercial Fe3O4 powder to prepare heterogeneousstructured Pt/Fe3O4 catalysts in the solution of ethylene glycol.The heterogeneous Pt/Fe3O4 catalysts achieved a better catalytic performance of CO oxidation compared with the Fe3O4 powder.The temperatures of 50%and 90%CO conversion were achieved above 260℃and 290℃at Pt/Fe3O4,respectively.However,they are accomplished on Fe3O4 at temperatures higher than 310℃.XRD,XPS,and H2-TPR results confirmed that the metallic Pt atoms have a strong synergistic interaction with the Fe3O4 supports.TGA results and transient DRIFTS results proved that the Pt metal particles facilitate the release of lattice oxygen and the formation of oxygen vacancies on Fe3O4.The combined results of O2-TPD and DRIFTS indicated that the activation step of oxygen molecules at surface oxygen vacancies could potentially be the rate-determining step of the catalytic CO oxidation at Pt/Fe3O4 catalysts.The reaction pathway involves a Pt-assisted Mars-van Krevelen(MvK)mechanism.

关 键 词：Strong metal-support interaction(SMSI) Surface oxygen vacancy Lattice oxygen MAGNETITE Platinum metals 

分 类 号：O64[理学—物理化学]