OXIDATION OF METHANOL AT COPPER SURFACES

The role of preadsorbed oxygen present at Cu(111), Cu(110) and polycry stalline surfaces in the oxidation of methanol has been investigated b y X-ray and electron energy loss spectroscopies. In addition to the we ll established formation of methoxy species and its subsequent decompo sition and desorption as formaldehyde, a second reaction pathway to su rface formate is present. The latter is temperature dependent being un detectable at 260 K at a polycrystalline surface but occurs at a signi ficant rate at 295 K and above. The limitations of experimental data f or methanol oxidation by temperature programmed desorption and molecul ar beam techniques are discussed.