Designing selective and durable electrodes for the electrochemical CO2 reduction reaction (eCO2RR) requires both efficient charge transport and favorable catalytic interfaces. Conventional carbon-based gas diffusion electrodes are unstable due to electrolyte flooding, whereas flood-resistant polytetrafluoroethylene (PTFE) substrates exhibit low electrical conductivity. Herein, a stacked-electrode architecture is reported to overcome these limitations, comprising PTFE as a porous substrate, Cu2O nanocubes as a catalyst layer, and Ag nanowire (Ag NW) networks as a current collector. The catalytic performance is highly dependent on the stacking sequence, with the PTFE/Cu2O/Ag configuration achieving remarkable C2+ selectivity and durability while exhibiting electrical resistance comparable to that of carbon paper. In alkaline electrolytes, this configuration exhibits a Faradaic efficiency toward C2+ (FEC2+) of 79% and stable operation for more than 50 h, significantly outperforming conventional carbon paper-based electrodes. Mechanistic studies reveal that the Ag NW networks not only ensure the coexistence of Cu(0)/Cu(I) species but also generate CO to drive tandem reactions, promoting C2+ production. Furthermore, it reaches an even higher FEC2+ of 86% while maintaining long-term stability under neutral electrolytes. These findings provide a versatile strategy for the rational design of durable and selective electrodes for eCO2RR.
Park et al. (Tue,) studied this question.