Kong Xiangdong, Wang Cheng, Xu Zifan, Zhong Yongzhi, Liu Yan, Qin Lang, Zeng Jie, Geng Zhigang
Hefei National Research Center for Physical Sciences at the Microscale, CAS Key Laboratory of Strongly-Coupled Quantum Matter Physics, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China.
Nano Lett. 2022 Oct 12;22(19):8000-8007. doi: 10.1021/acs.nanolett.2c02668. Epub 2022 Sep 9.
Mass transfer plays an important role in controlling the surface coverage of reactants and the kinetics of surface reactions, thus significantly adjusting the catalytic performance. Herein, we reported that HO diffusion was modulated by controlling the thicknesses of the carbon black (CB) layer between the gas diffusion electrode (GDE) of Cu and the electrolyte. As a consequence, the product distribution over the GDE of Cu was effectively regulated during CO electroreduction. Interestingly, a volcano-type relationship between the thickness of the CB layer and the faradaic efficiency (FE) for multicarbon (C) products was observed over the GDE of Cu. Especially, when the applied total current density was set as 800 mA cm, the FE for the C products over the GDE of Cu coated by a CB layer with a thickness of 6.6 μm reached 63.2%, which was 2.8 times higher than that (16.8%) over the GDE of Cu without a CB layer.
传质在控制反应物的表面覆盖率和表面反应动力学方面起着重要作用，从而显著调节催化性能。在此，我们报道了通过控制铜的气体扩散电极（GDE）与电解质之间炭黑（CB）层的厚度来调节HO扩散。结果，在CO电还原过程中，铜GDE上的产物分布得到了有效调控。有趣的是，在铜GDE上观察到CB层厚度与多碳（C）产物的法拉第效率（FE）之间存在火山型关系。特别是，当施加的总电流密度设定为800 mA cm时，涂覆有厚度为6.6 μm的CB层的铜GDE上C产物的FE达到63.2%，这比没有CB层的铜GDE上的FE（16.8%）高2.8倍。
