Metal-Organic Framework Derived Copper Catalysts for CO2 to Ethylene Conversion
Metal-Organic Framework Derived Copper Catalysts for CO2 to Ethylene Conversion
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用于二氧化碳转化为乙烯的金属有机骨架衍生铜催化剂
DOI：
10.1039/d0ta02395g
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发表时间：
2020
影响因子：
11.9
通讯作者：
Hongyan Liang
中科院分区：
文献类型：
--
作者：
Kaili Yao;Yujian Xia;Jun Li;Ning Wang;Jingrui Han;Congcong Gao;Mei Han;Guoqiang Shen;Yongchang Liu;Ali Seifitokaldani;Xuhui Sun;Hongyan Liang
将CO2电化学还原为乙烯为将CO2转化为增值燃料和原料提供了碳中性途径，因此有助于间歇性可再生电力的储存。具有高乙烯选择性和生产率的有效电催化剂的开发是非常期望的，但仍然具有挑战性。在这里，我们提出了一种基于铜的催化剂衍生自金属有机框架（Cu-MOF），表现出增强的性能，由于其多孔形态，复杂的氧化态和强的晶格应变。利用X射线衍射、X射线光电子能谱和X射线吸收光谱跟踪反应过程中晶体结构和氧化态的演变，结果表明Cu 2+离子迅速还原为Cu+，然后缓慢还原为Cu 0，形成Cu@CuxO核@壳结构。变形晶粒引起的拉伸应变有利于CO2的活化。通过稳定的Cu+形成的Cu+/Cu 0界面促进 *CO-CO二聚，促进向C2+产物的转化并抑制向C1产物的转化。优化的催化剂表现出51%的法拉第效率（FE）为乙烯和70%的FE为C2+产品，与20小时的操作稳定性在H-电池配置，和150 mA cm-2的部分乙烯电流密度在流通池配置。
The electrochemical reduction of CO2 to ethylene provides a carbon-neutral avenue for the conversion of CO2 to value-added fuels and feedstocks, so contributing to the storage of intermittent renewable electricity. The exploration of efficient electrocatalysts with high ethylene selectivity and productivity is highly desirable but remains challenging. Here, we present a Cu-based catalyst derived from a metal–organic framework (Cu-MOF) which shows enhanced performance due to its porous morphology, complex oxidation states and strong lattice strain. X-ray diffraction, X-ray photoelectron spectroscopy, and X-ray absorption spectroscopy are utilized to track the evolution of the crystal structure and oxidation states during the reaction, and the results reveal that Cu2+ ions are rapidly reduced to Cu+ and then slowly to Cu0, resulting in a Cu@CuxO core@shell structure. The tensile strain caused by the distorted grain is beneficial for the activation of CO2. Cu+/Cu0 interfaces formed through stabilized Cu+ facilitate *CO–CO dimerization, promoting conversion to C2+ products and suppressing conversion to C1 products. The optimized catalyst exhibits a 51% Faraday efficiency (FE) for ethylene and a 70% FE for C2+ products, with 20 h operational stability in an H-cell configuration, and a partial ethylene current density of 150 mA cm−2 in a flow-cell configuration.