Multi-channel ceramic catalytic membrane for highly efficient and continuous hydrogenation of p-nitrophenol.

A novel Co@CM catalytic membrane was fabricated by loading Co on the polydopamine modified multi-channel ceramic membrane and pyrolyzing under Ar atmosphere. Fine regulation of the dopamine concentration, cobalt nitrate concentration and pyrolysis temperature is in favor of achieving the Co@CM catalytic membrane with abundant Co nanoparticles, high surface Co content, and rich graphitic N, thereby intensifying the continuous reduction of p -nitrophenol to p -aminophenol in a flow-through catalytic membrane reactor. [Display omitted] • A Co@CM multi-channel ceramic catalytic membrane was designed and constructed. • The modification with dopamine can capture, reduce and protect Co via a CN layer. • The dopamine and Co concentrations obviously affect the microstructures of Co@CM. • The pyrolysis temperature significantly affects the microstructures of Co@CM. • Co@CM-3.0–0.1–700 can continuously, stably and fully convert 4-NP to 4-AP. The hydrogenation of p -nitrophenol (4-NP) to p -aminophenol (4-AP) transforms a detrimental pollutant into a valuable chemical, while conventional powder catalysts face challenges in continuous operation due to the limitations in separation and recovery processes. Here, we developed a catalytic membrane by loading Co onto a polydopamine (PDA)-modified multi-channel ceramic membrane (CM) with subsequent pyrolysis. PDA plays a crucial role in capturing Co ions, facilitating the reduction of Co ions, and preventing the leaching of Co nanoparticles (NPs) from the membrane. Fine-tuning the DA and cobalt nitrate concentrations, along with the pyrolysis temperature, results in the catalytic membrane with abundant Co NPs, enriched surface Co content, and sufficient graphitic N, which significantly enhances the reduction of 4-NP to 4-AP in a flow-through catalytic membrane reactor. The Co@CM-3.0–0.1–700 demonstrates a remarkable activity of converting 4-NP at a rate of 67.4 h−1, maintaining stability for a continuous operation of 300 min. This study pioneers highly efficient catalytic membrane for the transformation of detrimental pollutant 4-NP to a valuable chemical 4-AP. [ABSTRACT FROM AUTHOR]