Supported Nanostructured Mo x C Materials for the Catalytic Reduction of CO 2 through the Reverse Water Gas Shift Reaction.

Mo x C-based catalysts supported on γ-Al 2 O 3 , SiO 2 and TiO 2 were prepared, characterized and studied in the reverse water gas shift (RWGS) at 548-673 K and atmospheric pressure, using CO 2 :H 2 = 1:1 and CO 2 :H 2 = 1:3 mol/mol reactant mixtures. The support used determined the crystalline Mo x C phases obtained and the behavior of the supported nanostructured Mo x C catalysts in the RWGS. All catalysts were active in the RWGS reaction under the experimental conditions used; CO productivity per mol of Mo was always higher than that of unsupported Mo 2 C prepared using a similar method in the absence of support. The CO selectivity at 673 K was above 94% for all the supported catalysts, and near 99% for the SiO 2 -supported. The Mo x C/SiO 2 catalyst, which contains a mixture of hexagonal Mo 2 C and cubic MoC phases, exhibited the best performance for CO production.