Influence of the morphology of the oxide supports on catalytic performances of V/SiO₂ and V/MgO catalysts in methanol partial oxidation

A study was conducted to look at how turnover frequency in methanol oxidation varies as a function of vanadium weight loading. Important mechanistic information can be obtained by understanding how turnover frequency varies with vanadium weight loading. Using sol-gel prepared SiO₂ and MgO offers a mean for investigating this question because their high surface areas should allow more vanadium to be loaded without forming bulk phases. Methanol partial oxidation was applied as a chemical probe of both conventionally prepared- and aerogel prepared-V/SiO₂ and V/MgO catalysts. A decreasing trend of surface area was found with increased vanadium doping, with only few exceptions. Surfaces areas of all AP catalysts were at least twice as high as CP catalysts. Both catalysts produced CO_x (carbon dioxides and CO), dimethyl ether, and water. Other products, including formaldehyde, methyl formate, and dimethoxy methane, were generated when supported vanadium oxides were involved in the reaction. This is an abstract of a paper presented at the AIChE Annual Meeting and Fall Showcase (Cincinnati, OH 10/30/2005-11/4/2005).