Hypercrosslinked mesoporous polymers: Synthesis, characterization and its application for catalytic reduction of 4-nitrophenol

Abstract A mesoporous hypercrosslinked polymer (HCP), derived from a Friedel-Crafts alkylation reaction of 1,4-bis(chloromethyl)benzene and a precursor contained heterocyclic ionic liquids, was synthesized, having a high specific surface area with abundant mesopore and specific porosity. In order to reduce 4-nitrophenol (4-NP) to 4-aminophenol (4-AP), a new bismuth nanoparticle/HCP composite (Bi/HCP) as a catalyst was prepared, where the HCP was used as a catalyst carrier. Herein, the HCP was firstly impregnated into a BiCl3 solution to adsorb the Bi3+ ions. After that, these Bi3+ ions adsorbed were then reduced in situ using KBH4, affording the ultimate Bi/HCP composite. In such Bi/HCPs, Bi nanoparticles with a small diameter of 1–3 nm were evenly dispersed. In this work, the Bi/HCPs exhibit an excellent catalytic performance toward the reduction of 4-NP with a low loading, the reaction rate constant k is calculated to be 2.2 min−1, and the catalytic activity did not decrease even after 8 reaction cycles.