The selective oxidation of methanol: A comparison of the mode of action of metal and oxide catalysts

The reactivity of methanol towards oxygenated silver and copper substrates and towards the molecular oxide H4PVMo11O40 has been investigated by a variety of insitu techniques. The intention was to find the chemical origin of the selective action of atomic oxygen and to discuss the influence of the metal species on the oxygen reactivity. The exceptionally high reaction temperature over silver was traced back to the difficulty of forming one active oxygen species. Surface spectroscopies found evidence for three chemically inequivalent atomic oxygen species in the metal-oxygen systems in analogy to the three oxygen forms in the molecular oxide characterized by a single crystal structure analysis. The large body of surface science experiments in these systems has contributed to our understanding of the reaction possibilities but needs to be treated with reservation when a high pressure“ reaction mechanism is considered as these experiments describe only part of the system in the static limit of low chemical potential of the gas phase