Efficient and selective hydrogenation of quinolines over FeNiCu/MCM-41 catalyst at low temperature: Synergism of Fe-Ni and Ni-Cu alloys

•A series of FeNiCu/MCM-41 catalysts were successfully synthesized by the impregnation method.•A desired efficient and selective hydrogenation of quinolines was achieved at low temperature and in solvent-free system.•58% Fe4Ni6Cu5/MCM-41 catalyst achieved 97.5% conversion and exceeding 98% selectivity to tetrahydroquinoline under mild conditions.•Possible catalytic mechanism of the synergism of Fe-Ni and Ni-Cu alloys was proposed.