Modulating the Electrocatalytic CO2-CO Performance by Ag Morphology

Abstract

Highly selective conversion of CO2 into CO molecules remains a major challenge in electrocatalytic CO2 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 CO2 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 CO2 production over Ag-based catalysts, which can be further used as a guideline for catalyst development.