Combining catalysis and separation on a PVDF/Ag composite membrane allows timely separation of products during reaction process

• Microspheres decorated by Ag nanoparticles were immobilized in membrane pores.
• A cross-flow model of membrane was applied in catalysis for the first time.
• Rapid catalytic reaction was obtained under cross-flow operation.
• Reaction and separation were simultaneously realized by one-step operation.
• Catalysis operation was convenient, economical and environmentally-friendly.

The faced key issues for a catalytic reaction are improving catalytic reactivity, and decreasing the operating costs of separating products and catalysts from the treated system. These drawbacks are simultaneously overcomed for the first time by constructing a novel structured poly (vinylidene fluoride) (PVDF)/Ag hybrid membrane with microspheres decorated by Ag nanoparticles (NPs) in membrane pores, which is prepared by immersion precipitation phase inversion of the N,N-dimethylformamide solution containing poly (methacrylic acid) (PMAA) microspheres loaded by Ag nanoparticles and PVDF in aqueous solution. The as-formed hybrid membranes are used for the catalytic reduction of 4-nitrophenol under a cross-flow model. Results indicate this membrane prevents the agglomeration of Ag nanoparticles, improves the stability of Ag nanoparticles, having the advantages of a fast catalytic rate, a high efficiency and a long service life. Furthermore, using this membrane avoids the additional steps for separating metal NPs catalysts from reaction system. More importantly, products, for the first time, can be timely separated from the treated solution during the catalytic reaction process, which is ascribed to Ag NPs only in membrane pores.

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