The role of the support in CO hydrogenation selectivity of supported rhodium

Catalytic hydrogenation of CO offers tremendous challenges in catalyst design to control selectivity because of the large variety of hydrocarbons and oxygen-containing species that can be formed; Rh can produce the full range of potential products. Rh on SiO2, Al2O3, TiO2, CeO2 and MgO has been characterized by a complement of techniques and by CO hydrogenation activity. Catalytic activity varied over 200-fold, dependent on the support; Rh/TiO2 was the most active. Selectivity to alcohols vs. hydrocarbons and to methanol vs. ethanol varied over 50-fold. CO hydrogenation selectivity to alcohols varies with the basicity of the support; MgO, the most basic support, exhibited 90 % selectivity to methanol.