The dual-active-site tandem catalyst containing Ru single atoms and Ni nanoparticles boosts CO2 methanation

Hydrogenation of CO 2 into CH 4 is an effective strategy for dealing with CO 2 -relevant environmental problems. Since the CO 2 methanation reaction involves multiple electron transfers and various C1 intermediates, improving the reaction rate at each step is critical to accelerating the entire reaction. Here, we report a dual-active-site tandem catalyst (Ru 1 Ni/CeO 2 ) composed of Ru single atoms (Ru 1 ) and Ni nanoparticles , which can effectively convert CO 2 to CH 4 , showing ∼90% CO 2 conversion and ∼99% CH 4 selectivity at 325 °C, much higher than those of the Ru 1 /CeO 2 and Ni/CeO 2 catalysts. Experimental and theoretical calculation results reveal that Ru 1 is extremely active for converting CO 2 to CO, while the Ni site is highly efficient for the subsequent sequential CO to CH 4 reaction step. The coexistence of the Ru 1 and Ni sites significantly boosts the overall reaction. This work offers a promising strategy for the rational design of efficient multisite tandem catalysts.