Novel Pd/TiO2-Al2O3 Catalysts for Methane Total Oxidation at Low Temperature and Their 18O-Isotope Exchange Behavior

Pd supported on TiO2‐Al2O3 binary oxides prepared by coprecipitation method has been investigated for the total oxidation of methane. All Pd/TiO2‐Al2O3 catalysts show higher activity than Pd/Al2O3 and Pd/TiO2. Among them, Pd/2Ti‐3Al with a Ti/Al ratio of 2 to 3 has a T90% of 395 °C at a gas hourly mass velocity of 33000 mL/(h·g), which is at least 50 °C lower than that of Pd supported on single metal oxide Al2O3 or TiO2. The results of TPR and 18O‐isotope exchange experiments demonstrated that the excellent activity of Pd/2Ti‐3Al was due to its high oxygen mobility and moderate reducibility, which is in accordance with our previous work. XPS results indicated that the dispersion of Pd was not the key factor to influence the catalytic activity.