Enhanced selective hydrogenation of CO2 to CH4 on molybdenum carbide hollow sphere catalyst

Abstract Herein, methane (CH 4 ) production in carbon dioxide (CO 2 ) hydrogenation by hydrogen (H 2 ) is enhanced by reducing surface carbon deposits on molybdenum carbide (Mo 2 C) hollow spheres. When surface carbon deposits present on Mo 2 C hollow spheres, CO 2 conversion is 9.9%, and CO and CH 4 are both produced from CO 2 hydrogenation, with CO and CH 4 selectivity of 58.4% and 41.6%, respectively. When surface carbon deposits absent on Mo 2 C hollow spheres, CO 2 conversion increases to 18.6%, and CO 2 hydrogenation to CH 4 is enhanced, with a 100% CH 4 selectivity. Reducing surface carbon deposits on Mo 2 C hollow spheres changes the CO 2 adsorbed on Mo 2 C hollow spheres from a monodentate structure to a bidentate structure which prefers to undergo hydrogenation to CH 4 , thus enhancing CH 4 formation from CO 2 hydrogenation. These results open a new way to fabricate more efficient noble‐metal‐free catalysts for selective CO 2 hydrogenation.