Toluene Oxidation over the M-Al (M = Ce, La, Co, Ce-La, and Ce-Co) Catalysts Derived from the Modified "One-Pot" Evaporation-Induced Self-Assembly Method: Effects of Microwave or Ultrasound Irradiation and Noble-Metal Loading on Catalytic Activity and Stability

The mesoporous M-Al (M = Ce, La, Co, Ce -La, and Ce -Co) catalysts were synthesized by adopting a modified "one-pot" evaporation-induced self-assembly (EISA) strategy with ultrasound or microwave irradiation. The impact of Au or Pd on the physicochemical property and catalytic performance in toluene combustion was studied in detail. The 0.96 wt % Pd/Ce-Al catalyst prepared with microwave irradiation possessed the highest activity (the temperatures at toluene conversions of 10 and 90% were 209 and 350 degrees C at a gas hourly space velocity of 40 000 mL/(g h), respectively) and lowest apparent activation energy (100 kJ/mol). We conclude that large surface area, high adsorbed oxygen species concentration, and good low-temperature reducibility accounted for the excellent performance of the 0.96 wt % Pd/Ce-Al catalyst prepared with microwave irradiation.