The partial oxidation of methane to methanol: An approach to catalyst design

Abstract

In this study a new approach for the design of catalysts for methane partial oxidation to methanol is outlined and results arising from this approach are discussed. The approach involves identifying metal oxide catalyst components which activate methane and oxygen, but do not readily destroy methanol, the desired product. A series of catalysts based on MoO 3 and WO 3 were prepared by impregnation with solutions containing the metal ions of the second component. The Cu/MoO 3 catalyst showed a selectivity advantage over the homogeneous gas phase oxidation in a reactor bed packed with quartz chips. In general, the WO 3 based catalysts were less effective for the production of methanol. Additionally, catalysts composed from physical mixtures of Ga 2O 3 and ZnO with MoO 3 were prepared. The Ga 2O 3/MoO 3 catalyst showed a maximum methanol yield greater than the homogeneous gas phase reaction over an inert bed of quartz particles. The increased methanol yield was attributed to a synergistic effect combining the beneficial reactivities of the MoO 3 and Ga 2O 3 component oxides. Comparison with data obtained from an empty reactor tube showed that none of the catalysts were as active or selective for methane partial oxidation to methanol.