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

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 MoO3 and WO3 were prepared by impregnation with solutions containing the metal ions of the second component. The Cu/MoO3 catalyst showed a selectivity advantage over the homogeneous gas phase oxidation in a reactor bed packed with quartz chips. In general, the WO3 based catalysts were less effective for the production of methanol. Additionally, catalysts composed from physical mixtures of Ga2O3 and ZnO with MoO3 were prepared. The Ga2O3/MoO3 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 MoO3 and Ga2O3 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. (C) 1998 Elsevier Science B.V. All rights reserved.