Partial oxidation of CH4 over Al/silica catalysts using molecular oxygen

Partial oxidation of CH4 using molecular oxygen has been carried out over various commercial silicas and alumina doped silica catalysts using a flow reactor system. Partial oxidation products such as C2H6, C2H4, HCHO, CH3OH, and CO were formed over these catalysts as well as over a quartz reactor only. The presence of Al ions in silica remarkably enhanced the formation of C2H6, H2, HCHO, and CO even at low O2 concentrations. States of Al ions in silica were studied using MAS NMR of 27Al. The results indicated that tetrahedrally coordinated Al(4) ions seem to be present and be isolated in silica. The mechanism of CH4 oxidation is proposed under the heterogeneous participation of O2 activated on such sites.

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