High catalytic efficiency of Pd nanoparticles immobilized on TiO₂ nanorods-coated ceramic membranes

In this work, we designed and constructed an efficient and reusable membrane catalyst by loading palladium (Pd) nanoparticles on TiO₂ nanorods (NRs)-coated ceramic membrane. The morphology and structure analysis show that the TiO₂ NRs with a width of 200 nm–1000 nm and a length of about 4000 nm can be successfully synthesized on the ceramic membrane by a two-step hydrothermal method. The Pd nanoparticles with an average particle size of 4 nm can be uniformly distributed on the TiO₂ NRs-coated ceramic membrane. The catalytic performance evaluation highlights that higher catalytic activity and stability are observed for the Pd nanoparticles immobilized on the TiO₂ NRs-coated ceramic membrane compared to the ones loaded on the unmodified ceramic membrane in the liquid-phase p-nitrophenol hydrogenation. The TiO₂ NRs can provide more areas for the deposition of Pd nanoparticles, and then more Pd nanoparticles with better dispersion can be loaded on the membrane, leading to superior catalytic activity. The interaction between Pd nanoparticles and TiO₂ provides less leaching of Pd nanoparticles and higher catalytic stability.