Photocatalytic Assessment of Selective Distribution of Product Arising from Methanol Oxidation on Platinum-deposited TiO2 Mesoporous Layer in a Fixed-film UV Reactor

Abstract

The photocatalytic assessment of methanol conversion through cross-coupling reaction of methanol with its products was studied in a UV reactor consisting of platinum nanoparticles deposited onto a mesoporous TiO2 film. The temperature-programmed desorption (TPD) analysis showed excess methanol can affect the selective formation of formaldehyde, formic acid, and methyl formate (MF). The TPD results showed the methanol surface coverage, UV photon energy and irradiation time have mutual effects on the oxidation products. At saturated fraction of methanol coverage, formaldehyde was converted to MF and the desorption temperature of MF shifts to lower value. At 266 nm, the photooxidation reaction was more than two orders of magnitude faster than at 355 nm, suggesting that the selectivity of MF increases by the saturated fraction of methanol and increasing photon energy, while the formation of formaldehyde decreases at the same conditions. The formaldehyde conversion to formic acid gradually increases with increasing irradiation time.