3D graphene/nylon rope as a skeleton for noble metal nanocatalysts for highly efficient heterogeneous continuous-flow reactions

Abstract

Continuous-flow catalytic systems represent a highly efficient approach towards scalable synthesis with features of time and energy saving, easy operation, and improved safety. Herein, we rationally design a novel 3D noble metal/graphene/nylon rope to act as a highly efficient catalyst for continuous-flow organic reactions. We show that different noble metal (Pd, Pt, Au and Ag) nanocatalysts and graphene can be readily assembled with the chemically inert nylon rope by a one-step hydrothermal method. Graphene, acting as the interconnector for noble metal nanoparticles and the nylon rope, increases the flexibility and mechanical strength of rope-like catalysts and improves the catalytic activity and stability of the noble metal species. The large voids within the noble metal/graphene/nylon rope catalysts, under optimized reaction conditions, ensure the sufficient chemical transfer for the continuous-flow system. The high catalytic activity and stability of rope catalysts are demonstrated by the Suzuki–Miyaura cross-coupling reaction (SMC) and 4-nitrophenol reduction reaction. Pd/graphene/nylon rope catalysts show a high turnover number of 965 mol h⁻¹ mol_Pd⁻¹, a large productivity of 1385 mg h⁻¹ mg_Pd⁻¹ at a flow rate of 70 mL h⁻¹, and a remarkable stability for continuous-flow SMC reactions. Such a novel minifluidic system integrated with 3D noble metal/graphene/nylon rope catalysts can be extended to many important chemical reactions.