Rational Catalyst Layers Design Enables Tailored Transport Channels for Efficient CO2 Electrochemical Reduction to Multi-carbon Products

Abstract

Membrane electrode assemblies (MEAs) have been developed for electrochemical conversion of CO2 to high-value multi-carbon (C2+) products at industrial current densities (j>200 mA cm-2). However, the effective and simultaneous modulation of CO₂ and H₂O mass transfer within MEA remains a critical issue, particularly at the three-phase interface. Herein, CO2 and H2O channels are designed in the catalyst layer network to benefit the micro-environment. The balance of local CO2 and H2O at the reaction interface is attained by regulating the catalyst-coated ionomer. In-situ DEMS further confirms that the rational routes are successfully established for mass transfer management. The interfacial distribution of CO2 and H2O are in-depth investigated by in-situ ATR-SEIRAS and molecular dynamics (MD) simulation. By reasonable catalyst layers design, CO2-to-C2+ performance is substantially enhanced, which exhibits remarkable selectivity to C2+ products with a faradaic efficiency (FE) of 89.4±0.69% and a partial current density of 536±4.14 mA cm-2. The optimized Cu-GDE also exhibits excellent stability of >10h at a total current of 2 A.