Multi-channel ceramic catalytic membrane microreactors for highly efficient heterogeneous catalysis.

[Display omitted] • A Co@CM multi-channel ceramic catalytic membrane was designed and prepared. • The pyrolysis temperature, Co2+ concentration and solution cycle number are key. • Unstable Co@CN particles can be easily removed through forced flow flushing. • Co@CM-550–0.06–2 exhibits good activity and stability in p -nitrophenol reduction. • The p -nitrophenol reduction to p -aminophenol can be continuously performed. Multi-channel ceramic catalytic membrane microreactors are highly efficient reactors, combining reaction and separation in a single unit. However, the synthesis of multi-channel ceramic catalytic membranes with well-distributed active components keeps a great challenge. Here, we report a flow-induced layer-by-layer assembly of zeolitic imidazolate framework-67 (ZIF-67) followed by pyrolysis that generates highly active and well-distributed Co@N-doped carbon (Co@CN) catalytic materials inside the ceramic membrane (CM) pores, which creates abundant microreactors with enhanced mass transfer efficiency. The pyrolysis temperature, concentration of Co2+, and number of solution cycles are determined as pivotal factors on the microstructures and catalytic performance of the catalytic membranes. The catalytic membrane, Co@CM-550-0.06-2, exhibits outstanding performance in the reduction of p -nitrophenol to p -aminophenol, achieving full conversion within 25 min and maintaining stability over 5 h of continuous operation. The developed multi-channel ceramic catalytic membrane microreactors can be readily scaled up, and have great application potentials in heterogeneous catalysis. [ABSTRACT FROM AUTHOR]