Construction of Polydopamine@Crosslinked Polystyrene Core/Shell Polymeric Support for the Immobilization of Silver Nano‐cluster: Adsorption and Selective Reduction of p‐Chloronitrobenzene

Abstract

ABSTRACT Polymers are promising catalyst supports because of their tunable composition and facile functionality. In this work, a core/shell polydopamine@crosslinked polystyrene support (XP‐PDA) was first constructed, and silver nano‐clusters were subsequently immobilized via in situ reduction to yield Ag@XP‐PDA. Adsorption kinetic and temperature‐dependent isotherm tests were conducted to compare the adsorption capacity of the catalysts toward the reactant p‐chloronitrobenzene (P‐CNB) and its corresponding hydrogenation product p‐chloroaniline (P‐CAN). At 298 K, Ag@XP‐PDA reached adsorption equilibrium within 180 min, with distinct capacities of 38.5 mg g −1 for P‐CNB, whereas only 9.2 mg g −1 for P‐CAN. Increasing the temperature from 298 to 318 K enhanced the adsorption capacity for P‐CNB (from 50.3 to 54.1 mg g −1 ) while suppressing that for P‐CAN (from 15.3 to 11.6 mg g −1 ). This distinct temperature‐dependent adsorption behavior indicates the chemisorption of P‐CNB for substrate enrichment. Improved substrate adsorption and product desorption endow Ag@XP‐PDA with over 90% P‐CAN chemoselectivity at 318 K. Hence, the XP‐PDA support enables both the stabilization of Ag nano‐clusters and enrichment of the substrate, affording an efficient catalytic system for the selective reduction of P‐CNB to P‐CAN.