Modulating the Electrocatalytic CO₂-CO Performance by Ag Morphology

Highly selective conversion of CO 2 into CO molecules remains a major challenge in electrocatalytic CO 2 reduction reactions, and metallic silver-based materials have great potential. However, the selectivity and activity of traditional silver (Ag)-based materials cannot reach the desired level, and the development of new Ag-based materials has become a hot research topic. Here, novel ag-glomerated spore-shaped Ag nanomaterials are reported for the efficient reduction of CO 2 to CO. The unique nanostructures endowed with larger specific surface area, and the spore-like dispersed Ag nanoparticles (NPs) have more unsaturated Ag sites, which endowed the catalysts with higher intrinsic activity. Electrochemical tests show that spore-like Ag can obtain a Faraday efficiency (FE) of 95.6% at −1 V vs RHE, which is much higher than that of Ag nanowires (NWs) (73%) and ordinary Ag NPs (83%) synthesized in the same period. By using the three different morphologies of Ag synthesized as a research platform and statistically comparing the FE in the corresponding voltage interval, we obtained the influence of morphology effect on the selectivity of CO product production by electrocatalytic CO 2 production over Ag-based catalysts, which can be further used as a guideline for catalyst development.