Continuous and complete conversion of high concentration p-nitrophenol in a flow-through membrane reactor

Here, we report on a green and effective method for the continuous and complete conversion of high concentrations of p-nitrophenol (PNP) using a flow-through membrane reactor and less NaBH₄. The catalytic membrane was successfully fabricated by loading Pd nanoparticles onto the surface of a branched TiO₂ nanorod-functionalized ceramic membrane. The modification with branched TiO₂ nanorods can significantly improve the loading amount of Pd nanoparticles onto ceramic membranes, resulting in enhanced catalytic performance. With 6 mg of Pd, 93 L m⁻² hr⁻¹ of flux density and 8.04 cm² of membrane surface area in the flow-through membrane reactor, PNP at a concentration of 4,000 ppm can be converted to high-value p-aminophenol using less NaBH₄ (using a molar ratio of NaBH₄:PNP of 9.6) within 24 s at 30°C. More importantly, the conversion can be continuously and stably performed for 240 min.