Catalysts were prepared from ultra pure SiO2, Pd and Rh nitrates and chlorides, and by doping with Al, Fe, Na, K or Ca nitrate. The activities and selectivities of the Pd and Rh catalysts were investigated at 553 K, H-2/CO = 2 or 3 and 2.5 or 4 MPa respectively. Additives had a strong influence on the catalytic properties. The doping with alkali and alkaline earth oxides led to a strong suppression of the CO dissociation. Particularly basic additives, such as Ca, had a strong promoting effect on the methanol production. This may confirm that the formation of methanol occurs through formate intermediates.