Combining Nanoconfinement in Ag Core/Porous Cu Shell Nanoparticles with Gas Diffusion Electrodes for Improved Electrocatalytic Carbon Dioxide Reduction.

Bimetallic silver-copper electrocatalysts are promising materials for electrochemical CO 2 reduction reaction (CO 2 RR) to fuels and multi-carbon molecules. Here, we combine Ag core/porous Cu shell particles, which entrap reaction intermediates and thus facilitate the formation of C 2+ products at low overpotentials, with gas diffusion electrodes (GDE). Mass transport plays a crucial role in the product selectivity in CO 2 RR. Conventional H-cell configurations suffer from limited CO 2 diffusion to the reaction zone, thus decreasing the rate of the CO 2 RR. In contrast, in the case of GDE-based cells, the CO 2 RR takes place under enhanced mass transport conditions. Hence, investigation of the Ag core/porous Cu shell particles at the same potentials under different mass transport regimes reveals: (i) a variation of product distribution including C 3 products, and (ii) a significant change in the local OH - activity under operation.