Highly dispersed and stable Pd nano-catalyst loaded on chitosan nanoporous carbon microspheres for one-pot reductive amination of amines with aldehydes

Under the background of green/sustainable chemistry, it is still a challenge to synthesize green, efficient and stable catalysts for important chemical products. Herein, we reported a series of Pd nano-catalysts supported on chitosan nanoporous carbon microspheres (CNCM) derived from renewable resource chitosan, and used them for one-pot reductive amination of amines with aldehydes. Various physicochemical characterizations provided reliable evidences that the Pd nanoparticles (NPs) were uniformly dispersed on these CNCM with mean diameters from about 2.29–9.74 nm. As the carrier, CNCM had a nanoporous structure, which was conducive to the adhesion and dispersion of Pd NPs. Meanwhile, the inherent N/O-containing groups in CNCM and the formed defect interfaces during calcination process could anchor the Pd NPs firmly. These CNCM supported catalysts were utilized in the reaction of one-pot reductive amination, which showed excellent catalytic activity compared to various commercial Pd catalysts, as well good cyclic stability and broad substrate suitability.