Single Ru site dispersed Cu nanocluster dual sites enables outstanding photocatalytic CO2 reduction

Abstract

Abstract Cu-based catalysts are promising candidates for CO2 reduction owing to favorable energetics of Cu sites for CO2 adsorption and transformation. However, CO2 reduction involving insurmountable activation barriers and various by-products remains a significant challenge to achieve high activity and selectivity. Herein, a photocatalyst constructed with single-Ru-site-on-Cu-nanocluster on Bi4Ti3O12 exhibits exceptional activity and selectivity for CO2 conversion to CO. The Experimental and theoretical results consistently reveal that this unique atomic-level hierarchy allows the cascading transfer of photo-generated carriers to the surface Ru-Cu dual catalytic sites for closely interacting with CO2 molecules. Importantly, the d-band center of Cu undergoes a remarkable downshift after formation of Ru-Cu dual sites, while that of Ru is much more positive, thus collectively facilitating the adsorption of CO2, formation of crucial intermediate *COOH and desorption of CO to synergistically enhance the entire CO2 conversion process. The optimal BTOCu2Ru0.5 photocatalyst manifests a remarkable activity for selective reduction of CO2 to CO, yielding 10.84 µmol of CO with 15 mgcat after 4 h without any photosensitizer and sacrificial reagent, outperforming all bismuth-based materials and being one of the best photocatalysts ever reported. This work presents a strategy for rational design of multiple metal sites towards efficient photocatalytic reduction of CO2.