Enhanced mass transfer in three-dimensional single-atom nickel catalyst with open-pore structure for highly efficient CO2 electrolysis

Design of efficient catalysts for electrochemical reduction of carbon dioxide (CO2) with high selectivity and activity is of great challenge, but significant for managing the global carbon balance. Herein, a series of three-dimensional (3D) single-atom metals anchored on graphene networks (3D SAM-G) with open -pore structure were successfully mass-produced via a facile in-situ calcination technique assisted by NaCl template. As-obtained 3D SANi-G electrode delivers excellent CO Faradaic efficiency (FE) of >96% in the potential range of -0.6 to -0.9 V versus reversible hydrogen electrode (RHE) and a high current density of 66.27 mA cm(-2) at-1.0 V versus RHE, outperforming most of the previously reported catalysts tested in H-type cells. Simulations indicate that enhanced mass transport within the 3D open-pore struc-ture effectively increases the catalytically active sites, which in turn leads to simultaneous enhancement on selectivity and activity of 3D SANi-G toward CO2 electroreduction. The cost-effective synthesis approach together with the microstructure design concept inspires new insights for the development of efficient electrocatalysts. (C) 2021 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.

Automated summary

The study successfully synthesized a series of three-dimensional single-atom metal catalysts using a facile in-situ calcination technique assisted by NaCl template. These catalysts showed excellent CO selectivity and activity, with potential applications in CO2 electrochemical reduction.