Structure-performance correlation on bimetallic catalysts for selective CO2 hydrogenation

CO2 hydrogenation to C1 chemicals has attracted significant interest due to the increasing demand for energy and global warming. Continuous efforts in the field of heterogeneous catalysis have revealed that CO2 hydrogenation is structure-sensitive in monometallic catalysts. However, fundamental research into the structure-performance relationship in bimetallic catalysts is a big challenge because the well-defined bimetallic structures and the corresponding mechanism are more complex than those of monometallic ones. Here, with the construction of TiO2 supported Ni–Ru bimetallic catalysts, evidenced by advanced microscopy characterizations, the alloyed and non-alloyed structures have been synthesised for hydrogenation. The in situ experiments show that the Ni–Ru bimetallic structures act like an ‘H-atom valve’ via control of the H2 spillover, which can completely switch the CO2 hydrogenation selectivity during the reaction. These findings bring a fundamentally new understanding of the selective hydrogenation on bimetallic nanocatalysts and the structure-performance relationship in controlling the ‘H-atom valve’ for many important chemical processes.