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

Mesoporous M-Al (M = Ce, La, Co, Ce-La, and Ce-Co) catalysts were fabricated by adopting the modified "one-pot" evaporation-induced self-assembly strategy with ultrasound or microwave irradiation. In addition, influence of the noble metal (Au or Pd) on physicochemical property and catalytic activity for toluene combustion of the material was investigated in detail. The samples derived with microwave irradiation and loading of Au or Pd possessed a coral architecture shape and a high surface area of 252–366 m2/g, with the noble metal nanoparticles being well dispersed on the sample surface. The 0.96 wt% Pd/Ce-Al sample prepared with microwave irradiation presented the lowest apparent activation energy (100 kJ/mol) and the best catalytic performance, with the light-off temperature at 10 % toluene conversion and the temperature at 90 % toluene conversion being 209 and 350 οC at a space velocity of 40,000 mL/(g h), respectively. Long-term (60 h) stability and effects of 40 ppm SO2, 3 or 5 vol% water vapor, and...