Synthesis, characterization, and catalytic activities of mesostructured aluminophosphates assembled with preformed MFI zeolite nanoclusters

Highly stable mesostructured heteroatom-substituted AlPOs (Al-JQW-5 and Ti-JQW-5) have been successfully synthesized by assembly of MFI zeolite nanoclusters with quaternary alkylammonium surfactants under alkaline conditions. Al-JQW-5 shows a stronger acidity than conventional SAPOs using TEOS as a silica source and Ti-JQW-5 exhibits high catalytic activities in both small molecular oxidation (phenol hydroxylation) and bulky molecular oxidation (2,3,6-trimethylphenol hydroxylation). These samples have also been characterized by X-ray diffraction, transmission electron microscopy, N2 adsorption, infrared, UV-visible spectroscopy, and a number of other techniques, and the local environment of Al, P and Si has been investigated by MAS NMR. The characterization results indicate that Al-JQW-5 and Ti-JQW-5 contain primary and secondary structural building units of MFI zeolite, which may be responsible for the stronger acidity or higher redox activities.