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 reduction reaction (CORR) 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 products at low overpotentials, with gas diffusion electrodes (GDE). Mass transport plays a crucial role in the product selectivity in CORR. Conventional H-cell configurations suffer from limited CO diffusion to the reaction zone, thus decreasing the rate of the CORR. In contrast, in the case of GDE-based cells, the CORR 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 products, and (ii) a significant change in the local OH activity under operation.