METHYL NITRITE ADSORPTION AS A NOVEL ROUTE TO THE SURFACE METHOXY INTERMEDIATE

Surface-bound methoxy species are intermediates in a variety of surfac e processes, ranging from heterogeneous catalysis to advanced fuel cel ls, yet their chemistry on many metals remains elusive because of the difficulty of cleanly preparing adsorbed layers of these species. We p ropose that thermal dissociation of an adsorbed precursor, methyl nitr ite (CH3ONO), can be used to produce methoxy species on reactive metal surfaces at low temperatures. On two Pt-Sn alloys, the methoxy interm ediate is strongly stabilized (to 300 K) against thermal decomposition compared to Pt(111), where dissociation occurs at below 140 K, and th ere is a high selectivity to produce formaldehyde. These Pt-Sn alloys do not form the CO and H-2 dissociation products characteristic of met hoxy chemistry on Pt(111).