N-Doped graphene fiber anchored Pd nanoparticles as a fixed-bed catalyst for continuous-flow reduction of N-containing unsaturated compounds

Catalytic fixed-bed is an efficient and facile system for scalable organic synthesis due to its continuous and fast flow operation process.As a key unit in the fixed-bed system,catalytically active packing materials are required to possess some properties,such as high activity,excellent stability,and porous packing structure.Herein,we prepare a fibrous fixed-bed catalyst by anchoring Pd nanoparticles on N-doped graphene fiber(NHG)(Pd/NGF).Due to the porous and loose packing structure,the resultant Pd/NGF catalyst can be easily filled into the continuous-flow reactor to construct a fixed-bed system with low flow resistance.The corresponding catalytic fixed-bed system exhibits a favourable flow rate(8 mL/min)and excellent durability toward reduction reactions of N-containing unsaturated compounds to produce aromatic amines.This work provides a new design concept of fibrous fixed-bed catalysts with dual-active components(i.e.,graphene-derived active materials and metal nanoparticles)and catalytic organic synthesis in a continuous-flow process.