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

Abstract

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.