A Review of CO2 Reduction Reaction Catalyzed by Atomical-Level Ag Nanomaterials: Atom-Precise Nanoclusters and Atomically Dispersed Catalysts

Electrochemical CO2 reduction reaction (CO2RR) provides a lucrative avenue to convert greenhouse gas CO2 into valuable products to balance the carbon cycle by coupling with intermittent renewable energy resources. Yet, the current catalysts are suffering from sophisticated preparation, high cost, low activity, undesirable product selectivity, and more importantly, the inhomogeneous nature at the atomical-level for comprehensive mechanism study. Atomical-level Ag nanomaterials have been gaining considerable research attentions as efficient CO2RR catalysts in the past a few years, thanks to the easy synthesis, relatively low cost, excellent activity, high selectivity toward CO formation, and well-defined structure for establishing the structure-performance relationship. In this review, we first discuss the recent progress of employing atomical-level Ag nanomaterials including atom-precise nanoclusters and atomically dispersed catalysts toward CO2RR. Specifically, the well-defined structure with corresponding advanced characterizations and in-depth structure-activity correlations of these two types of Ag nanocatalysts are elucidated. Subsequently, the common challenges and some specific perspectives for CO2RR catalyzed by them are analyzed. Finally, this review is closed with a brief conclusion.