Microenvironment engineering by targeted delivery of activated Ag NPs for boosting electrocatalytic CO2 reduction reaction

Abstract

To boost the performance of electrocatalytic CO₂ reduction reaction (eCO₂RR), a unique synthetic method that deploys the in situ reduction of precoated precursors was developed to produce activated Ag nanoparticles (NPs) within the gas diffusion layer (GDL), where the thus-obtained Ag NPs-Skeleton could block direct contact between the active Ag sites and electrolyte. Specifically, compared to the conventional surface loading mode in the acidic media, our freestanding and binder free electrode could achieve obvious higher CO selectivity of 94%, CO production rate of 23.3 mol g^-1 h^-1, single-pass CO₂ conversion of 58.6%, and enhanced long-term stability of 8 hours. Our study shows that delivering catalysts within the GDL does not only gain the desired physical protection from GDL skeleton to achieve a superior local microenvironment for more efficient pH-universal eCO₂RR, but also manifests the pore structures to effectively address gas accumulation and flood issues, thereby stabilizing the catalysts.