Bimetallic FeIr/SiO2 catalysts that are active for methanol prodn. from synthesis gas (CO + H2) bind CO less strongly, and exhibit higher activity for the hydrogenation of ethylene in the presence of CO, than catalysts that produce mainly methane. It is argued that promotion of the noble metal serves to weaken the adsorption of CO, thereby lowering its tendency to dissoc., and, most importantly, enhancing the surface coverage of hydrogen. Both factors are favorable for methanol formatio