Fully dispersed site catalysts for the reverse water-gas shift reaction: recent advances and perspectives

The reverse water gas shift (RWGS) reaction enables the conversion of CO₂ and renewable H₂ into CO, providing an important way for the resource utilization of CO₂. However, its practical application is still limited by the balance of catalytic activity, CO selectivity and high-temperature stability. As these catalytic properties are closely associated with the structure and coordination environment of the active sites, precisely regulating the active sites represents an effective strategy for improving RWGS performance. Fully dispersed site catalysts (FDSCs), including isolated atoms, or subnanometric clusters (<1 nm), offer unique opportunities for atomic-scale control over active-site structures and coordination environments. Therefore, this review summarizes recent advances in FDSCs for RWGS. Firstly, bottom-up construction and top-down redispersion strategies are summarized, highlighting the roles of metal nuclearity, support defects, and interfacial electronic structures in determining the formation and stability of fully dispersed sites. The applications of noble-metal (Pt, Pd, Rh, and Ru) and non-noble-metal (Fe, Co, Ni, and Cu) FDSCs in RWGS are then summarized, focusing on the effects of metal composition and site structure on CO₂ activation, H₂ dissociation, key intermediate conversion, and CO desorption, as well as the resulting catalytic performance. Finally, future research should integrate operando characterization, theoretical calculations, and artificial intelligence to unravel the dynamic structure–activity relationships of fully dispersed sites, thereby accelerating the rational design of efficient and stable RWGS catalysts.