Highly selective electrochemical CO2 reduction to CO using a redox-active couple on low-crystallinity mesoporous ZnGa2O4 catalyst
Highly selective electrochemical CO2 reduction to CO using a redox-active couple on low-crystallinity mesoporous ZnGa2O4 catalyst
复制标题
在低结晶度介孔 ZnGa2O4 催化剂上使用氧化还原活性对高选择性电化学 CO2 还原为 CO
DOI：
10.1039/c9ta00562e
复制
发表时间：
2019
影响因子：
11.9
通讯作者：
Zou Zhigang
中科院分区：
文献类型：
--
作者：
Zhao Meiming;Gu Yaliu;Chen Ping;Xin Zhenyu;Zhu Heng;Wang Bing;Zhu Kai;Yan Shicheng;Zou Zhigang
由于CO2活化的大量过电位、复杂的CO2还原途径和竞争性的H2析氢反应（HER），由于其低能量效率和产品选择性，限制了基于CO2的电化学能量转换和存储技术的实际应用。在此，我们提出了一种结合介孔和氧化还原活性偶联的策略来有效地捕获CO2并选择性地生成CO产物。作为一个例子，我们在低结晶度的介孔ZnGa2O4电催化剂上构建了氧化还原活性偶对Zn2+/Zn+。介孔不仅能有效捕获CO2，还能抑制H2的析出。低结晶度的弱晶格约束有利于形成Zn2+/Zn+氧化还原偶对，与CO2分子强烈相互作用，进行后续的活化和催化转化，从而有效降低CO2对活性物质CO2 -的活化能，加速质子转移形成关键的COOH*中间体。结果表明，该催化剂在−1.4 V相对于Ag/AgCl（−0.8 V相对于RHE）的较低电位下，在zn基电极中表现出96%的高法拉第效率，并且在0.1 M KHCO3溶液中运行10小时具有优异的稳定性。
The substantial overpotential of CO2 activation, the complex CO2 reduction pathway, and the competitive H2 evolution reaction (HER) limit the practical applications of CO2-based electrochemical energy conversion and storage technologies due to their low energy efficiency and product selectivity. Here, we proposed a strategy that combines mesopores and redox-active couple to effectively capture CO2 and selectively generate CO product. As an example, we construct a redox-active couple, Zn2+/Zn+, on the low-crystallinity mesoporous ZnGa2O4 electrocatalyst. The mesopores not only help to capture CO2 effectively but also inhibit the H2 evolution. The weak lattice constraint of low crystallinity benefits the formation of a Zn2+/Zn+ redox couple to strongly interact with CO2 molecule for subsequent activation and catalytic conversion, thus effectively decreasing the activation energy of CO2 to the active species CO2− and accelerating the proton transfer to form the crucial COOH* intermediate. Consequently, this catalyst exhibited a high faradaic efficiency of 96% among Zn-based electrodes for CO generation at the relatively low applied potential of −1.4 V vs. Ag/AgCl (−0.8 V vs. RHE), and excellent stability during 10 h operation in a 0.1 M KHCO3 solution.