Synthesis gas conversion over a Rh–K–MoP/SiO2 catalyst

Synthesis gas conversion over a 1 wt% Rh–5 wt% K–10 wt% MoP on SiO2 catalyst was investigated at different temperatures, synthesis gas H2/CO ratios and space velocities. Compared to a 5 wt% K–10 wt% MoP on SiO2 catalyst, addition of Rh increased the stability of the catalyst and the selectivity to hydrocarbons. The highest C2+ oxygenate selectivity of 44 C atom% was achieved at 598 K and H2:CO = 1. Power law kinetics were used to describe the space–time yield (STY) of the major products. The apparent activation energies for ethanol (77.7 kJ/mol) and acetaldehyde (81.9 kJ/mol) formation suggested that both originated from the same surface intermediate whereas, a higher activation barrier was identified for methanol (114.5 kJ/mol).