Converting CO2 to multi-carbon products at >1 A/cm2 using gas diffusion electrode based on commercial materials via transfer process engineering

Abstract

Cu-based gas diffusion electrodes for the electrocatalytic conversion of CO2 to high-value-added multi-carbon products is a promising technology. However, it is in urgent demand to develop high-efficiency electrode and electrolyzer to promote its poor reaction kinetics and product selectivity, which have seriously hindered its industrial application. Herein, the hydrophobicity property and the pore size distribution of microporous layer (MPL) and the hydrophobicity property of carbon fiber substrate (CFS) were studied to adjust electron transfer, CO2 transfer, and water transfer, which creates a microenvironment more suitable for the production of multi-carbon products. It is shown, by this strategy, ampere-level current density (1.36 A/cm2) is obtained using a gas diffusion electrode based entirely on commercially available materials, with partial current density of 0.697 A/cm2 and 0.885 A/cm2 for ethylene and C2+ products at −1.44V vs. RHE. Further characterizations show that the CO2 transfer via CFS and MPL to catalyst layer (CL) and water transfer determine CL local CO2 concentration and wettability to further influence the gas-liquid ratio and the coverage of *CO2, *H, and *CO on the catalyst surface to promote CC coupling and thus yield an optimal selectivity of C2+ products.