PARTIAL OXIDATION OF METHANE BY NITROUS OXIDE OVER MOLYBDENUM ON SILICA.

Article abstract of DOI:10.1021/ja00327a009

Molybdenum supported on silica is a catalyst for the selective oxidation of methane to methanol and formaldehyde when nitrous oxide is the oxidant and steam is present in the system. At a conversion level of 3% the combined selectivity to CH//3OH and HCHO is 78%, with CO being the principal other product. Spectroscopic evidence indicates that the reaction is initiated by the formation of reactive O** minus ions which are coordinated to Mo**V**I at the surface. The O** minus ions are capable of hydrogen atom abstraction from CH//4, and the resulting methyl radicals rapidly react with the surface to form methoxide complexes. The methoxide may decompose to form HCHO or it may react with water to form CH//3OH. In this cycle molybdenum begins and ends in the V oxidation state. The nonselective oxidation of methane occurs (a) when Mo**V**IO**2** minus is formed or (b) when the products CH//3OH and HCHO are more fully oxidized.