Catalysis Today, Vol.33, No.1-3, 73-83, 1997
Partial Oxidation of Methane to Formaldehyde on Silica-Supported Transition-Metal Oxide Catalysts
This work describes the partial oxidation of methane on high surface area silica-supported redox oxide catalysts (MO(x)/SiO2; M = V, Mo, W and Re). Formaldehyde, C2Hn, and CO2 are primary products obtained in this reaction, while CO originates from further oxidation of formaldehyde and hydrocarbons. Supported vanadium oxide was found to be the most reactive due to its higher reducibility, thus providing additional sites for oxygen activation. Rhenium oxide exhibited high specific activity and selectivity, however it deactivates from sublimation of metal oxide under on-stream operation at high temperatures, typically above 773 K. Results suggest a reaction scheme where oxygenates and oxygen-free intermediates are present yielding HCHO, COx and C2Hn hydrocarbons.
Keywords:GAS-PHASE REACTIONS;SELECTIVE OXIDATION;MOLYBDENUM OXIDE;OXYGEN;RAMAN;METATHESIS;PATHWAYS;SITES