Amine-Capped Co Nanoparticles for Highly Efficient Dehydrogenation of Ammonia Borane

Highly efficient heterogeneous catalysts are desired for the development of new energy storage materials. The rational choice and use of capping ligands are of significant importance for performance optimization of metal nanoparticle (NP) catalysts. By exploiting amine-rich polyethylenimine (PEI) and graphene oxide (GO) as a NP support, we demonstrate that as a capping ligand, PEI deposited on GO provides a novel pathway able to simultaneously control the morphology, spatial distribution, surface active sites of cobalt (Co) NPs, and remarkably enhances their catalytic properties for the hydrolytic dehydrogenation of ammonia borane (AB). Such a synergistic effect enables the synthesized PEI-GO/Co catalysts to reveal extremely high dehydrogenation activities under atmosphere condition. A total turnover frequency of 39.9 mol(H2) min(-1) mol(Co)(-1) and an apparent activation energy of 28.2 kJ mol(-1) make the catalytic performance of these PEI-GO/Co catalysts comparable to those of noble metal-based catalysts, including bimetallic and multimetallic catalysts.