MECHANISM OF METHANOL ADSORPTION-REACTION OVER GALLIUM OXIDES

S. COLLINS; M BALTANÁS; A. BONOVARDI; L. BRIAND; L. GAMBARO

Toledo. España

Congreso; Operando-II. Second International Congress on Operando Spectroscopy; 2006

The chemisorption of probe molecules is well a known method to characterize the surface of catalytic materials. Recently, the chemisorption of methanol was proved as a reliable method to determine the nature and number of surface active sites of oxide catalysts. Briand et al. demonstrated that methanol chemisorbs as a stable monolayer of methoxy species on an oxide surface exposed to an atmosphere of 2000 ppm of methanol at 373 K. These species are the intermediates in the synthesis, selective oxidation/dehydration and steam reforming of methanol. Methanol chemisorption and surface reaction over bulk gallium oxides (alpha, beta and gamma polymorphs) were obtained through the investigation of the surface intermediate species and product desorption (TPSR-MS and TPSR-FTIR experiments) during the surface reaction of adsorbed methoxy species.