Molybdenum carbide clusters for thermal conversion of CO2 to CO via reverse water-gas shift reaction

Molybdenum carbides are highly active for CO2 conversion to CO via the reverse water-gas shift (RWGS) reaction, however the large grain size up to micrometers renders its relatively lower active sites utilization efficiency while generating CH4 as a by-product. In this work, a homogeneously dispersed molybdenum carbide hybrid catalyst with sub-nanosized cluster (the average size as small as 0.5 nm) is pre pared via a facile carbothermal treatment for highly selective CO2-CO reduction. The partially disordered Mo2C clusters are characterized by synchrotron high-resolution XRD and atomic resolution HAADF-STEM analysis, for which the source cause of the disorder is pinpointed by XAFS analysis to be the nitrogen intercalants from the carbonaceous precursor. The partially disordered Mo2C clusters show a RWGS rate as high as 184.4 mu mol g(-1) Mo2C s(-1) at 400 degrees C with a superior selectivity toward CO (> 99.5%). This work highlights a facile strategy for fabricating highly dispersed and partially disordered Mo2C clusters at a sub-nano size with beneficial N-doping for delivering high catalytic activity and operational stability. (c) 2020 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.