Restructuring of copper catalysts by potential cycling and enhanced two-carbon production for electroreduction of carbon dioxide. (February 2022) - Wen, Jingbo
Highlights: The copper oxides are reduced to metallic state under cathodic reduction condition. The potential cycling induces surface reconstruction of Cu catalysts. Growth of Cu dendrites increase with the cycling laps. The selectivity towards multi-carbon products from CO2 R is remarkably enhanced. In 1 M KOH solution, the Faradaic efficiency of C2+ is 34.1 %, at a current density reaches 80 mA/cm 2 . Abstract: The activity and selectivity of electrocatalytic CO2 reduction (CO2 R) is strongly dependent on the structure of the catalyst. Structural engineering is always at the heart of preparing the high-performance catalysts. Herein, mixed copper oxide catalysts were prepared by a hydrothermal method, which consisted of Cu4 O3, CuO and Cu2 O. The potential cycling of this Cu oxide catalyst in 1 M KHCO3 electrolyte resulted in metallic state of smaller particles and Cu nanowires, as manifested by scanning electron microscopy and X-ray diffraction. The catalytic performance of the restructured Cu catalysts towards two carbon products in CO2 R were much enhanced compared to the pristine catalyst, as explored in flow cell reactor on gas diffusion electrode. In 1 M KOH solution, the Faradaic efficiency of two-carbon products is 34.1 % at –0.8 V vs. reversible hydrogen electrode, and the partial current density reaches 80 mA/cm 2 on gas diffusion electrode.