A dual promotional effect of doping tantalum (Ta) in atomically dispersed Ru/CeO2 catalyst toward CO2 methanation: Enhanced associative adsorption of CO2 and activation of H2

Precisely controlling the product selectivity in CO 2 hydrogenation through rational catalyst design presents a promising approach to mitigate environmental and energy-related challenges, though it remains a significant scientific hurdle. Herein, the CH 4 selectivity of 0.5 wt% Ru loaded catalysts at 250 °C was effectively shifted from approximately 35 % to 100 % through the incorporation of Ta dopant into the CeO 2 support. The EXAFS spectra in conjunction with CO DRIFTS experiment indicated the presence of atomically dispersed Ru particles anchored on the Ta-doped CeO 2 surface. A higher oxidized CeO 2 surface was evidenced in the presence of Ta dopant. The presence of Ta dopant also improved the dispersion of Ru species and their interaction with the support. Most importantly, the Ru/Ta-CeO 2 catalyst exhibited a pronounced capacity for associative CO 2 -adsorption under atmospheric pressure at 50 °C. An improved H 2 activation was also observed under CO 2 hydrogenation conditions. This novel finding of the dual promotional effect of Ta carries a significant impact in the field of CO 2 capture and utilization. • A novel Ru/Ta-CeO 2 catalyst was prepared for selective methanation of CO 2 . • Atomically dispersed Ru particles were anchored on the Ta-CeO 2 surface. • A higher oxidized CeO 2 surface was evidenced in the presence of Ta dopant. • The Ru/Ta-CeO 2 catalyst exhibited a remarkable CO 2 adsorption capacity. • H 2 activation was significantly improved on the Ru/Ta-CeO 2 surface under CO 2 methanation conditions.