US EPA

2454679 

Journal Article 

A comparative study of the partial oxidation of methane to formaldehyde on bulk and silica supported MoO3 and V2O5 catalysts 

Parmaliana, A; Arena, F; Sokolovskii, V; Frusteri, F; Giordano, N 

1996 

Yes 

Catalysis Today
ISSN: 0920-5861 

28 

4 

363-371 

WOS:A1996VH94200008 

The mechanism of the partial oxidation of methane to formaldehdye with O-2 has been investigated on bulk and differently loaded silica supported (4-7 wt%) MoO3 and (5-50 wt%) V2O5 catalysts at 600-650 degrees C in a pulse reactor connected to a quadrupole mass spectrometer. The reaction rate and product distribution in the presence and in the absence of gas-phase O-2 have been evaluated. On bare SiO2, low and medium loaded silica supported MoO3 and V2O5 catalysts the reaction proceeds via a concerted mechanism involving the activation of gas-phase oxygen on the reduced sites of the catalyst surface as proved by the direct correlation between catalytic activity and density of reduced sites evaluated in steady-state conditions, while on highly loaded catalysts as well as on bulk MoO3 and V2O5 the reaction rate drops dramatically and the reaction pathway via redox mechanism becomes predominant. The results indicate that the surface mechanism is essentially more effective than the redox mechanism enabling also a higher selectivity to HCHO. 

comparative study; partial oxidation of methane to formaldehyde; bulk and silica supported MoO3 and V2O5 catalysts; MoO3; V2O5