Overcoming the Strong Metal-support Interaction in Ni Clusters/TiO2 Catalyst for Selective CO2 Hydrogenation

The reverse water gas shift (RWGS) reaction is an essential step for CO2 hydrogenation, in which developing efficient and low-cost catalysts is highly desirable. Because of the excellent catalytic property in hydrogenation reaction, Ni nanoparticles are used as catalysts for CO2 methanation. However, Ni nanoparticles are very susceptible to strong metal-support interaction (SMSI) with reducible oxides at high temperatures, preventing its applications in the RWGS reaction. Hence, we develop a strategy to prepare SMSI-resistant Ni-clusters onto the surface of hydroxylated TiO2. The nickel atoms were deposited on the hydroxylated TiO2 in single-atom form and subsequently transformed to clusters with an average particle size of 1 nm after hydrogen treatment. The coating phenomenon of Ni by TiO2 due to the SMSI effect is avoided, so as to achieve the enhanced catalytic performance and excellent stability at as high as 600 C for the RWGS reaction. The strategy developed in this work pave a way for fabricating SMSI-resistant metal catalysts that can widely utilized in sustainable catalysis reactions.