In Situ Electropolymerizing Toward EP‐CoP/Cu Tandem Catalyst for Enhanced Electrochemical CO2‐to‐Ethylene Conversion

Abstract

Abstract Electrochemical CO2 reduction has garnered significant interest in the conversion of sustainable energy to valuable fuels and chemicals. Cu‐based bimetallic catalysts play a crucial role in enhancing *CO concentration on Cu sites for efficient C─C coupling reactions, particularly for C2 product generation. To enhance Cu's electronic structure and direct its selectivity toward C2 products, a novel strategy is proposed involving the in situ electropolymerization of a nano‐thickness cobalt porphyrin polymeric network (EP‐CoP) onto a copper electrode, resulting in the creation of a highly effective EP‐CoP/Cu tandem catalyst. The even distribution of EP‐CoP facilitates the initial reduction of CO2 to *CO intermediates, which then transition to Cu sites for efficient C─C coupling. DFT calculations confirm that the *CO enrichment from Co sites boosts *CO coverage on Cu sites, promoting C─C coupling for C2+ product formation. The EP‐CoP/Cu gas diffusion electrode achieves an impressive current density of 726 mA cm−2 at −0.9 V versus reversible hydrogen electrode (RHE), with a 76.8% Faraday efficiency for total C2+ conversion and 43% for ethylene, demonstrating exceptional long‐term stability in flow cells. These findings mark a significant step forward in developing a tandem catalyst system for the effective electrochemical production of ethylene.

Keywords

• cobalt porphyrin
• electrochemical CO2 reduction
• in situ electropolymerizing
• multi‐carbon products
• tandem catalyst