Electrochemical CO2 reduction on copper offers a route to valuable fuels and chemicals, but performance depends strongly on electrolyzer design, which is not yet well understood due to the multiscale complexity coupling kinetics and transport. Here, we address this using a first-principles multiscale modeling framework for gas diffusion electrodes. By constructing digital twins of previously reported experimental electrolyzers, the simulations identify two critical cell design parameter groups which control spatial product selectivity: (1) Electrochemical surface area of the catalyst, which governs current densities across the catalyst layer and voltage range; and (2) catalyst support properties, which govern activity near the gas inlet at high currents.Under the latter conditions, high out-flux of gaseous products blocks the incoming CO2 gas, a process strongly influenced by substrate pore size. We also present evidence for product selectivity regions within the catalyst layer, and their sensitive dependence on GDE design. This work extends the scope of first-principles simulations to shed important light into the multi-scale complexity of modern electrolyzers.
DOI 링크: https://doi.org/10.1039/D6EE02654K
