Atomically dispersed Pt/CeO2 catalyst with superior CO selectivity in reverse water gas shift reaction

Platinum (Pt)-based catalysts often failed to possess high CO2 conversion and high CO selectivity at the same time (especially at high reaction temperature) in reverse water gas shift (RWGS) reaction. Herein, we found that atomically dispersed Pt species was the crucial factor in improving the selectivity of CO and inhibiting the formation of CH4. Three Pt/CeO2 catalysts, including atomically dispersed Pt species, and Pt clusters or particles with different sizes, were synthesized. It was found that the atomically dispersed Pt/CeO2 catalyst led to an outstanding CO selectivity (>98 %) in the temperature range of 200∼450 °C, while the CO selectivities over Pt nanoparticles decreased conspicuously as the reaction temperature increased. CO-TPD and in situ FTIR experiments demonstrated that CH4 was produced by the further hydrogenation of CO. And the atomically dispersed Pt species had the relatively weak adsorption strength toward CO, which prevented excessive hydrogenation and promoted CO selectivity in RWGS reaction. Our investigation provides a new thinking for designing the RWGS reaction catalyst with an outstanding CO selectivity and emphasize the significance of atomically dispersed catalysts in catalytic reactions again.