Oxidation of methanol on different silica supported lithium molybdates

The adsorption, the temperature programmed desorption and the oxidation of methanol were studied on different silica supported Li2MoO4. It was found that after adsorption of methanol methoxy species were formed in all cases, but the thermal stability of these species were different. The lowest value was found on Li2MoO4/aerogel. Oxygen in the gas phase stabilizes the surface methoxy groups up to 600–650 K. TPD spectra of adsorbed methanol show that up to 620 K only CH3OH and HCHO desorbed but at higher temperatures CO2, CH4 and H2 were also formed. In the oxidation of CH3OH the rate of HCHO formation was the highest on aerogel supported Li2MoO4 at 533 K, and the selectivity was more than 70%.