Unraveling and optimizing the metal-metal oxide synergistic effect in a highly active Co_(x)(CoO)_(1–x) catalyst for CO_(2) hydrogenation  

作　　者：Kun Zhao Marco Calizzi Emanuele Moioli Mo Li Alexandre Borsay Loris Lombardo Robin Mutschler Wen Luo Andreas Zuttel 

机构地区：[1]Laboratory of Materials for Renewable Energy,Institute of Chemical Sciences and Engineering,tcole Polytechnique Federale de Lausanne(EPFL),1951 Sion,Switzerland [2]Swiss Federal Laboratories for Materials Science and Technology(EMPA),8600 Diibendorf,Switzerland

出　　处：《Journal of Energy Chemistry》2021年第2期241-250,I0009,共11页能源化学（英文版）

基　　金：financially supported by Innosuisse, the Swiss Innovation Agency, is gratefully acknowledged;The NAPXPS system is funded by the SNSF R’EQUIP project (No. 170736);the financial support from SNSF (Ambizione Project PZ00P2_179989);the China Scholarship Council for the PhD grant (Grant No. 201506060156)。

摘　　要：The relation between catalytic reactivities and metal/metal oxide ratios, as well as the functions of the metal and the metal oxides were investigated in the CO_2 hydrogenation reaction over highly active Co_x(CoO)_(1–x)catalysts in operando. The catalytic reactivity of the samples in the CO_2 methanation improves with the increased Co O concentration. Strikingly, the sample with the highest concentration of CoO, i.e., Co_(0.2)(CoO)_(0.8), shows activity at temperatures lower than 200 °C where the other samples with less CoO are inactive. The origins of this improvement are the increased amount and moderate binding of adsorbed CO_2 on CoO sites. The derivative adsorption species are found to be intermediates of the CH4 formation. The metallic Co functions as the electronically catalytic site which provides electrons for the hydrogenation steps. As a result, an abundant amount of CoO combined with Co is the optimal composition of the catalyst for achieving the highest reactivity for CO_2 hydrogenation.

关 键 词：Cobalt and cobalt oxide REACTIVITY CO_(2)hydrogenation Active site Adsorption Activation energy 

分 类 号：TQ426[化学工程] X701[环境科学与工程—环境工程]