Ni Single Atoms Confined in Nitrogen-Doped Carbon Nanotubes for Active and Selective Hydrogenation of CO2 to CO

Developing efficient non-precious-metal catalysts capableof selectivelyconverting CO2 into fuels and chemicals is desirable yetremains a challenge. Ni-based catalysts usually exhibit high activityin methanation reactions but low selectivity and stability in thereverse water-gas shift (RWGS) reaction. Herein, we report a Ni single-atomcatalyst with Ni-N- x motifs confinedin N-doped carbon nanotubes as an active, selective, and stable catalystfor the RWGS reaction, achieving almost 100% CO selectivity with aSTY of 1.88 mol(CO) g(Ni) (-1) h(-1) at 500 degrees C and atmospheric pressure. In additionto weak CO adsorption, strong CO2 adsorption and weak H-2 adsorption at the Ni-N- x active site were found to be responsible for the high catalyticactivity and CO selectivity.