Switching CO 2 Electroreduction Selectivity Between C 1 and C 2 Hydrocarbons on Cu Gas‐Diffusion Electrodes
Switching CO 2 Electroreduction Selectivity Between C 1 and C 2 Hydrocarbons on Cu Gas‐Diffusion Electrodes
复制标题
在 Cu 气体扩散电极上切换 C 1 和 C 2 烃之间的 CO 2 电还原选择性
DOI：
10.1002/eem2.12307
复制
发表时间：
2022
影响因子：
15
通讯作者：
Wu, Jingjie
中科院分区：
文献类型：
--
作者：
Zhang, Jianfang;Li, Zhengyuan;Cai, Rui;Zhang, Tianyu;Yang, Shize;Ma, Lu;Wang, Yan;Wu, Yucheng;Wu, Jingjie
调节对目标碳氢化合物的选择性仍然是CO2电还原的重点。在这里，我们发现铜气体扩散电极中原始的表面铜物种比表面粗糙度、局部pH和刻面在控制对C2或C2烃的选择性方面起着更重要的作用。随着铜氧化物种比例的降低，对C2H4的选择性逐渐增加，而CH4的选择性稳步下降。在较低的电沉积电压(1.5 V)下，具有最高铜δ+/CuO比的铜气体扩散电极有利于氢化生成甲烷的途径，最大法拉第效率为65.4%，部分电流密度为228 mA cm−2at−0.83 V vs RHE。在2 V时，铜δ+/Cu0比值最低的铜气体扩散电极倾向于C-C偶联生成C2+产物，在−为0.75 V时法拉第效率高达80.1%，其中C2H4的法拉第效率为46.4%，C2H4的部分电流密度达到279 mA cm−2。
Regulating the selectivity toward a target hydrocarbon product is still the focus of CO2electroreduction. Here, we discover that the original surface Cu species in Cu gas‐diffusion electrodes plays a more important role than the surface roughness, local pH, and facet in governing the selectivity toward C1or C2hydrocarbons. The selectivity toward C2H4progressively increases, while CH4decreases steadily upon lowering the Cu oxidation species fraction. At a relatively low electrodeposition voltage of 1.5 V, the Cu gas‐diffusion electrode with the highest Cuδ+/Cu0ratio favors the pathways ofhydrogenation to form CH4with maximum Faradaic efficiency of 65.4% and partial current density of 228 mA cm−2at −0.83 V vs RHE. At 2.0 V, the Cu gas‐diffusion electrode with the lowest Cuδ+/Cu0ratio prefers C–C coupling to form C2+products with Faradaic efficiency topping 80.1% at −0.75 V vs RHE, where the Faradaic efficiency of C2H4accounts for 46.4% and the partial current density of C2H4achieves 279 mA cm−2. This work demonstrates that the selectivity from CH4to C2H4is switchable by tuning surface Cu species composition of Cu gas‐diffusion electrodes.