文献类型：期刊文献

英文题名：Origin of extraordinarily high catalytic activity of Co₃O₄ and its morphological chemistry for CO oxidation at low temperature

作者：Wang, Hai-Feng[2];Kavanagh, Richard[1];Guo, Yang-Long[2];Guo, Yun[2];Lu, Guanzhong[2];Hu, P.[1,2]

机构：[1]Queens Univ Belfast, Sch Chem & Chem Engn, Belfast BT9 5AG, Antrim, North Ireland;[2]E China Univ Sci & Technol, Labs Adv Mat, Res Inst Ind Catalysis, Shanghai 200237, Peoples R China

年份：2012

卷号：296

起止页码：110

外文期刊名：JOURNAL OF CATALYSIS

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000312427100011)】；

基金：This project was supported financially by National Basic Research Program of China (2013CB933201, 2010CB732300) and 111 Project (B08021). P.H. thanks the Chinese Government for the program of "Thousands Talents".

语种：英文

外文关键词：CO oxidation; Metal oxides; DFT

摘要：Understanding and then designing efficient catalysts for CO oxidation at low temperature is one of the hottest topics in heterogeneous catalysis. Among the existing catalysts. Co3O4 is one of the most interesting systems: Morphology-controlled Co3O4 exhibits exceedingly high activity. In this study, by virtue of extensive density functional theory (OFT) calculations, the favored reaction mechanism in the system is identified. Through careful analyses on the energetics of elementary reactions on Co3O4(1 1 0)-A, Co3O4(1 1 0)-B, Co3O4(1 1 1) and Co3O4(1 0 0), which are the commonly exposed surfaces of Co3O4, we find the following regarding the relation between the activity and structure: (i) Co3+ is the active site rather than Co2+: and (ii) the three-coordinated surface oxygen bonded with three Co3+ may be slightly more reactive than the other two kinds of lattice oxygen, that is, the two-coordinated 0 bonded with one Co2+ and one Co3+ and the three-coordinated 0 bonded with one Co2+ and two Co3+. Following the results from Co3O4, we also extend the investigation to MnO2(1 1 0), Fe3O4(1 1 0), CuO(1 1 0) and CuO(1 1 1), which are the common metal oxide surfaces, aiming to understand the oxides in general. Three properties, such as the CO adsorption strength, the barrier of CO reacting with lattice 0 and the redox capacity, are identified to be the determining factors that can significantly affect the activity of oxides. Among these oxides, Co3O4 is found to be the most active one, stratifying all the three requirements. A new scheme to decompose barriers is introduced to understand the activity difference between lattice O-3c and O-2c on (1 1 0)-B surface. By utilizing the scheme, we demonstrate that the origin of activity variance lies in the geometric structures. (C) 2012 Elsevier Inc. All rights reserved.