In summary, the sulfated Pt/TiO₂-S catalysts were preparedby impregnating with sulfuric acid solution. The sulfation of TiO₂ causes the supported Pt/TiO₂-S catalysts to severely deactivate towards methane combustion. It is found that sulfation of TiO₂ supports suppresses the formation and stability of highly reactive Pt²⁺ species during methane oxidation process, weakens the adsorption of CH₄ molecule, and raises activation energy barrier of the first C-H bond, eventually leading to a sharp decline in activity.