The kinetics of CO2 reforming of CH4 were studied over Pt supported on TiO2, ZrO2, Cr2O3, and SiO2, and the catalysts were characterized using chemisorption, X-ray diffraction, diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), temperature-programmed hydrogenation (TPH), and temperature-programmed surface reaction. Although the Pt/SiO2 and Pt/Cr2O3 catalysts deactivated significantly within 5 and 15 h onstream, respectively, the Pt/ZrO2 and Pt/TiO2 catalysts exhibited much higher stability even after 80 to 100 h onstream. TPH results with used catalysts showed that both Pt/ZrO2 and Pt/TiO2 have suppressed carbon deposition under reaction conditions. H-2 and CO chemisorption as well as DRIFTS provided evidence of metal-support interactions in the Pt/TiO2 catalyst and indicated that large ensembles of Pt atoms, active for carbon deposition, are deactivated or destroyed by the presence of mobile TiOx species. Activities for CO formation and CH4 consumption on a turnover frequency basis were five times greater on Pt/TiO2 compared with the other catalysts, suggesting that active sites for reforming are created in the Pt-TiOx interfacial region. The kinetic behavior was explained well by a kinetic model recently proposed for supported Ni.