Performance of organic–inorganic hybrid catalysts based on Ia-3d mesoporous silica

✍ Scribed by Yoshihiro Kubota; Chunshi Jin; Takashi Tatsumi

• Publisher: Elsevier Science
• Year: 2008
• Tongue: English
• Weight: 627 KB
• Volume: 132
• Category: Article
• ISSN: 0920-5861
• DOI: 10.1016/j.cattod.2007.12.033

✦ Synopsis

The cubic Ia-3d mesoporous silica with ordered large pores was synthesized from tetraethoxysilane (TEOS) and a small amount of 3mercaptopropyltorimetoxysilane (MPTS) as the silica sources under the acidic conditions by using triblock copolymer P123 (EO 20 PO 70 EO 20 ) as a surfactant. After removal of the surfactant by the solvent extraction method, mercaptopropyl (MP) group (-CH 2 CH 2 CH 2 SH) remained inside pores with a slight loss. The pore diameter of this mesoporous silica was about 5 nm. After converting the MP group to sulfopropyl (SP) group (-CH 2 CH 2 CH 2 SO 3 H) by the oxidation with H 2 O 2 , the amount of organic group was significantly reduced. However, it was possible to introduce additional organic groups by post-synthetic grafting. It was also possible to graft both MP and SP groups at the same time, and cooperative effect was observed in the acid-catalyzed condensation reaction of phenol with acetone. More organics were immobilized to the multi-dimensional cubic Ia-3d structure than the one-dimensional 2d-hexagonal structure. The catalyst having both SH and SO 3 H groups showed much higher selectivity for bisphenol A than Amberlyst 15 and Nafion SAC-13, which could be explained by the SH group-assisted mechanism.