A highly active silica(silicon)-supported vanadia catalyst for C1 oxygenates and hydrocarbon production from partial oxidation of methane

A very low surface area silica-silicon substrate has been used as a support for vanadium oxide and has been tested in the partial oxidation of methane. Use of a reactor with variable dead volume ahead of the bed of the catalyst allows determining the relevance of gas phase reactions in initiating methane conversion. Experimental evidence supports that at atmospheric pressure C₁ oxygenates are essentially produced on the catalyst surface rather than in the gas phase. Comparison with a high surface area silica-supported vanadium oxide catalyst clearly highlights the double role of surface area in promoting catalytic activity, but also in promoting non-selective further oxidation of reaction products. It is shown that a reaction system combining dead volume upstream the bed of the catalyst and a very low surface area is very promising to activate methane conversion to C₁ oxygenates and C₂₊ hydrocarbons at remarkable TOF number preventing further non-selective oxidation. In addition, production of C₂₊ hydrocarbons is observed at temperatures as low as 750 K.