The Effect of the Presence of Ceria on the Character of TiO2Mesoporous Films Used as Pt Catalyst Support for Methanol Combustion at Low Temperature

A series of ceria-doped mesoporous TiO2 thin films with anatase phase are synthesized and used as the support of platinum catalysts for low-temperature catalytic combustion of methanol. Since the methanol combustion on the catalysts can usually generate local overheating, which unavoidably leads to the structure destruction and catalytic activity loss, the structure thermal stability of catalytic material is very important. Results show that an appropriate amount of ceria can improve the mesoporous order and especially structure thermal stability of TiO2 thin films. For the TiO2 film (calcined at low temperature of 350°C)-supported Pt catalysts, the catalytic activity of ceria-doped catalysts with ceria dosage of 1–2 mol% is comparable to that of the Pt/TiO2 catalyst without ceria doping and the methanol conversion on these kinds of catalysts is about 70% at room temperature. However, for those TiO2 films calcined at 550°C, under the same reaction condition, methanol conversion on Pt/TiO2 drops to 27% but the conversion on Pt/Ceria-TiO2 with the same small ceria dosage of 1–2 mol% can still be kept as 43%. Moreover, after 72 h reaction at room temperature, the catalytic activity has not changed obviously, which means that the stability of the Pt/Ceria-TiO2 catalyst is very high.