Enhanced selectivity of the CO2 reverse water-gas reaction over a Ni2P/CeO2 catalyst.

Abstract

Ni catalysts tend to easily undergo methanation and metal sintering at high temperatures during the CO2 hydrogenation reaction. Herein, Ni2P, a typical kind of transition metal phosphide, had been demonstrated to be efficient for use in the reverse water gas (RWGS) reaction. Under weight hourly space velocity (WHSV) values of 150\u2009000 and 300\u2009000 mL g-1 h-1, the Ni2P/CeO2 catalyst presented a high CO selectivity, better than that of the conventional Ni/CeO2 catalyst. The activity was also well maintained in a 20 h stability test. Detailed physicochemical characterization proved that the moderate adsorption strength of CO2, as well as more strong adsorption active sites for H2 on the Ni2P/CeO2 surface, prevented the CO2 from further hydrogenating to CH4, which accounted for the remarkable CO selectivity and stability of the CO2 RWGS reaction.