A series of Si-doped mesoporous TiO2 thin films with anatase phase were synthesized and used as the supporters of Pt catalyst for low-temperature catalytic combustion of gaseous methanol. The introduced Pt ions were processed by a simple photo-reduction method. The catalytic performance of thin film catalysts with different Si doping content were measured by gas chromatography method. It was found that the catalytic performance of Pt/TiO2 can be improved a lot by Si doping and the optimized value of Si/Ti ratio is 0.1. At this point, Pt/TiO2 exhibited the best catalytic activity towards methanol combustion reaching up to 92.8% at 100 degrees C. This conversion rate was 13.2% higher than that of the catalyst without doping. Moreover, the mechanism for Si affecting on the catalytic performance was proposed based on the XRD, FT-IR, SEM, TEM, N-2 adsorption-desorption and XPS characterizations. (C) 2014 Elsevier B.V. All rights reserved.