Dual-atom-site photocatalysts enhanced CO2 reduction coupled with benzylamine oxidation

Solar-driven artificial photosynthesis via CO 2 reduction represents a promising method for generating renewable feedstock in a sustainable manner. However, CO 2 activation is very demanding and the separation of undesired O 2 as by-product is challenging. Promoting the oxidation of organic substances by consuming photo-generated holes can effectively prevent O 2 production, improving energy conversion, product selectivity and separation. In this study, we report a photosensitizer-functionalized (tris(2,2′-bipyridyl)ruthenium, PS) dual-atom-site [Ru(C 10 N 2 H 4 ) 2 Cl 2 ]H 4 [Ru 2 Cl 2 (CH 3 COO) 4 ]·H 2 O ( PS-Ru 2 ) photocatalyst that promotes the conversion of CO 2 to CO with the photooxidation of benzylamine to liquid benzylidenebenzylamine, enabling facile separation without additional photosensitizers or sacrificial agents in a single redox cycle. This is the first reported dual-atom-site photocatalytic system to promote an artificial photosynthetic CO 2 reduction coupled with benzylamine oxidation, delivering high activity, selectivity and separability. Modification of the photosensitizer resulted in an eleven-fold increase in yield, representing a significant advancement in catalytic CO 2 photoreduction. The findings of this study establish a novel dual-atom-site catalyst design strategy that facilitates dual-functional artificial photosynthesis, enabling by-product reuse with improved performance.