Pd nanoparticles immobilized on TiO ₂ nanotubes-functionalized ceramic membranes for flow-through catalysis

A high performance catalytic membrane was fabricated with Pd nanoparticles supported by TiO ₂ nanotubes, where the TiO ₂ nanotubes were synthesized on the ceramic membrane via a simple hydrothermal etching. A flow-through catalytic membrane reactor was developed for testing the catalytic properties in the p-nitrophenol reduction. The effect of etching time was investigated in detail and an optimal etching time was determined to be 16 h. The characterization results highlighted that the as-prepared bouquet-like TiO ₂ nanotubes could significantly improve the loading amount and dispersity of Pd nanoparticles. The fabricated catalytic membrane exhibited considerably improved catalytic activity and stability, with a 100% conversion of p-nitrophenol and no loss in catalytic activity during five reaction cycles. The obtained activation energy was much lower than the values in literatures, implying that the p-nitrophenol reduction could take place more easily on our catalytic membranes compared to other catalysts.