Synthesis and Acidity Enhancement of SBA-15

SBA-15 molecular sieve was prepared according to a procedure reported by Ooi and Bhatia (2007). In 300 mL of deionized water and 40 mL of hydrochloric acid (37 %) for 1 h at 323 K, 9.8 g of triblock copolymer poly(ethylene oxide)- poly(propylene oxide)-poly(ethylene oxide) (average molecular weight = 5,800) was dissolved with stirring. Next, 21.7 g of tetraethylorthosilicate was added and stirred for another 10 min. The mixture was then heated at 333 K and then at 373 K for 24 h under stirring. The solid product obtained was filtered, dried at 100 °C, and then calcined in air at 500 °C. Four grams of SBA-15 was dispersed in 100 mL solution of AlCl3 and refluxed at 353 K with stirring for 2 h. The aluminum-containing mesoporous catalyst was then filtered, thoroughly washed with deionized water, dried at room temperature, and finally calcined at 823 K for 4 h.