Catalytic properties of the novel mesoporous aluminosilicate AlTUD-1

The novel mesoporous three-dimensional amorphous aluminosilicate, an excellent catalyst carrier denoted as AlTUD-1, was prepared with different Si/Al ratios using a surfactant-free one-pot synthesis with triethanolamine as the template. Characterization of this material by means of XRD and N2 sorption showed that it is mesoporous with a specific surface area as high as 925 m2/g. The mesoporosity was further supported by HR-TEM results. 27Al-MAS-NMR spectra of the calcined AlTUD-1 samples proved that almost 60% of Al was tetrahedrally coordinated. NH3-TPD of AlTUD-1 samples revealed that the number of acid sites decreased and the strength of acid sites increased with increasing Si/Al ratio. The acid sites observed were mainly Lewis acid sites, and the Brønsted acidity generated from Al in tetrahedral coordination was observed to be weak. This novel material with a relatively low aluminum content was shown to be a versatile catalyst for the alkylation of phenol in the gas phase as well as in the liquid phase with tert-butyl alcohol and methyl tert-butylether, respectively. This demonstrates that a variation in Si/Al ratio can convert a catalyst carrier into a catalyst itself.