TiH₂-supported Ru catalyst with unusual electron transfer behaviour for highly efficient carbon dioxide methanation at low temperature

Catalytic CO2 methanation is of particular significance and growing interest due to its applications in many important industrial fields. The development of advanced heterogeneous catalysts for CO2 methanation depends predominantly on the rational regulation of metal-support interaction (MSI), which remains challenging despite recent progress. Here, we develop a new heterogeneous catalyst, TiH2-supported Ru nanoparticles (NPs), which features notable electron transfer from the TiH2 support to Ru NPs and enhanced capability of CO intermediate activation for CO2 methanation, distinct from TiO2-supported Ru catalysts synthesized under similar mild conditions. The electron transfer behavior and hydrogen spillover effect in TiH2-supported Ru NPs (denoted as mRTH, where m refers to the mass loading of the RuCl3 precursor in mg) are optimized at a moderate Ru loading level of 9.8 wt% in 100RTH, where the impacts of Ru loading on CO intermediate activation, H-2 activation and catalyst surface hydration are synergistically balanced. When evaluated at 200 & DEG;C under 4 bar pressure, 100RTH delivers a notable CH4 selectivity of 99.8% and a superior CH4 production rate of 168.7 mmol h(-1) g(Ru)(-1), which is 21.1 times more active than pure Ru NPs. Our work provides valuable insights into the MSI-directed development of heterogeneous catalysts for highly efficient CO2 conversion and utilization.