Catalytic chemistries for the conversion of dimethyl ether to oxygenates

The emergence of DME as a chemical intermediate has created opportunities for its conversion into useful products. The smaller amount of co-produced water (relative to methanol reactants) leads to products which higher purity and weaker kinetic inhibition effects. The selective oxidation of DME to formaldehyde on catalysts based on dipersed MoO_x and VO_x domains, and selective carbonylation of DME to methyl acetate on acidic zeolites were investigated. Kinetic, isotopic, and spectroscopic data were consistent with a sequence of elementary steps initiated by methylation of acid sites and limited by CO addition to the resulting methyl groups to form acetyl species, which then desorbed as methyl acetate in fast methylation reactions without the concurrent formation of water and re-formation of methyl groups. This is an abstract of a paper presented at the 231th ACS National Meeting (Atlanta, GA 3/26-30/2006).