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 Kun Zhao;Marco Calizzi;Emanuele Moioli;Mo Li;Alexandre Borsay;Loris Lombardo;Robin Mutschler;Wen Luo;Andreas Züttel

作者机构：Laboratory of Materials for Renewable EnergyInstitute of Chemical Sciences and Engineeringtcole Polytechnique Federale de Lausanne(EPFL)1951 SionSwitzerland Swiss Federal Laboratories for Materials Science and Technology(EMPA)8600 DiibendorfSwitzerland 

出 版 物：《Journal of Energy Chemistry》 (能源化学（英文版）)

年 卷 期：2021年第30卷第2期

页      面：241-250,I0009页

核心收录：

学科分类：0820[工学-石油与天然气工程] 083002[工学-环境工程] 0830[工学-环境科学与工程（可授工学、理学、农学学位）] 0808[工学-电气工程] 08[工学] 0817[工学-化学工程与技术] 0807[工学-动力工程及工程热物理] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 0827[工学-核科学与技术] 0703[理学-化学] 

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)。 

主　　题：Cobalt and cobalt oxide Reactivity CO_(2)hydrogenation Active site Adsorption Activation energy 

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.