Hydrogenation of CO over RhVO4/SiO2 catalyst -: Detection and elimination of deposited carbon and regeneration of RhVO4-

CO hydrogenation over RhVO4 catalyst on SiO2 support (RhVO4/SiO2) was investigated after H-2 reduction at 573 K. RhVO4 catalyst was formed on the SiO2 Support by calcination in air at 973 K with an atomic ratio of V/Rh = 1. RhVO4 was decomposed to Rh metal particles and highly dispersed V oxide particles by H-2 reduction, and a strong metal-oxide (Rh-vanadium oxide) interaction (SMOI) was induced. The RhVO4/SiO2 catalyst after H-2 reduction showed higher activity and selectivity for C-2 oxygenates in CO hydrogenation, compared with unpromoted Rh/SiO2 catalyst. The activity of the RhVO4/SiO2 catalyst decreased after intentional deactivation treatment (at 513 K in a stream of the reaction gas for 10 h; CO conversion of 100%). Temperature-programmed oxidation (TPO) of the deactivated RhVO4/SiO2 catalyst resulted in formation of CO2. Therefore, the deactivation was probably due to carbon deposition. RhVO4 on the SiO2 Support was regenerated by recalcination in O-2 at 873 K, and the activity and selectivity for C-2 oxygenates were restored.