Partial Oxidation of Methane to Synthesis Gas over Rhodium Vanadate, RhVO4: Redispersion of Rh Metal during the Reaction

Article abstract of DOI:10.1246/bcsj.65.2562

Partial oxidation of methane to synthesis gas (CO+H2) has been carried out over both RhVO4/SiO2 and unpromoted Rh/SiO2 catalysts at temperatures between 300 deg C and 720 deg C and 1 atmosphere pressure, with a CH4:O2 of 2:1 under nitrogen dilution.It is found that the RhVO4 compound supported on SiO2 was reduced to Rh metal and V2O3 during the reaction, and the catalyst showed onset of activity to CO and H2 around 500 deg C reaching a maximum conversion in excess of 90percent at 650 deg C, while the unpromoted Rh/SiO2 catalyst showed the onset of activity at the higher temperature (above 600 deg C) reaching almost 100percent conversion at around 700 deg C.The different catalytic activity may be ascribed to both the morphology change (Rh dispersion) and the Rh-vanadia interaction after the reduction of the RhVO4 compound.