ZIF-Derived Co/Zn Bimetallic Catalytic Membrane with Abundant CNTs for Highly Efficient Reduction of p-Nitrophenol

Design and synthesis of cheap and high-efficiency catalytic membranes are of great significance for green chemical engineering. Herein, we report a Co/Zn bimetallic catalytic membrane (CoZn@CM) through a self-sacrificial template approach, where Co/Zn zeolitic imidazolate framework (Co/Zn-ZIF) was first in situ grown on the ceramic membrane (CM) and then pyrolyzed under Ar atmosphere. Adjusting the Co2+ concentration during the synthesis of Co/Zn-ZIF@CM and the pyrolysis temperature can achieve the catalytic membrane of CoZn@CM with rich carbon nanotubes (CNTs) on the membrane, lots of Co nanoparticles with a smaller particle size and a large number of mesopores, thereby improving its catalytic activity for the liquid-phase p-nitrophenol hydrogenation to p-aminophenol in a flow-through catalytic membrane reactor. The as-fabricated Co0.2Zn0.4–920@CM exhibits excellent catalytic activity, which is about 2.7 times that of Co0Zn0.6–920@CM and 2.4 times that of Co0.2Zn0.4–770@CM. Moreover, Co0.2Zn0.4–920@CM can keep its catalytic performance after five reaction cycles of p-nitrophenol hydrogenation.