Preparation and catalytic performance of Ti-MWW zeolite membrane for phenol hydroxylation

A novel and dense tubular Ti-MWW zeolite membrane for the phenol hydroxylation was successfully prepared on mullite support by secondary hydrothermal synthesis. The ultraviolet-visible spectroscopy and fourier transform infrared spectrometer confirmed that the Ti species was thetetrahedrally coordinated state in zeolite framework. Plenty of pure phase sheet Ti-MWW zeolite crystals were fully covered on the support surface, the Ti/Si molar ratio and thickness of the Ti-MWW zeolite layer were 0.016 and 5 mu m by X-ray photoelectron spectroscopy and scanning electron microscope characterization results, respectively. The membrane showed good catalytic performance for phenol hydroxylation under pervaporation condition at 323 K. The phenol conversion and dihydroxybenzene selectivity were 22.94% and 98.33%, respectively.