Cu nanoparticles coated with porous N-doped carbon for the selective hydrogenation of quinolines under mild conditions

The rational design and construction of high-performance heterogeneous non-noble metal catalysts is an urgent need for the practical application of selective hydrogenation of quinoline and its derivatives. In this work, N-doped porous carbons encapsulated highly-dispersed Cu nanoparticles catalyst (Cu@NC-900) was synthesized by pyrolysis of Cu-metal-organic framework (MOF) precursor, based on the design concept of high efficiency, low cost, and excellent durability. Interestingly, the Cu@NC-900 catalyst exhibits extremely high activity, chemo-selectivity, and recoverability for the hydrogenation of quinoline and its derivatives using ammonia borane as the hydrogen resources under mild conditions. The characterization results of powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectrum, X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDS), and density functional theory (DFT) calculations revealed that the doped N and highly-dispersed Cu species in the catalyst can change the electronic density of the catalyst surface, and thus improve the hydrogenation catalytic performance. This study provides a new idea for rational design of high-performance non-noble metal catalysts for hydrogenation of quinolines under mild conditions.