In Situ Electropolymerizing Toward EP-CoP/Cu Tandem Catalyst for Enhanced Electrochemical CO 2 -to-Ethylene Conversion.

Electrochemical CO ₂ 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 C ₂ product generation. To enhance Cu's electronic structure and direct its selectivity toward C ₂ 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 CO ₂ 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 C ₂₊ 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 C ₂₊ 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.
(© 2024 The Author(s). Advanced Science published by Wiley‐VCH GmbH.)