Synergetic Catalysis of Non-noble Bimetallic Cu–Co Nanoparticles Embedded in SiO2Nanospheres in Hydrolytic Dehydrogenation of Ammonia Borane

Ultrafine non-noble bimetallic Cu–Co nanoparticles (∼2 nm) encapsulated within SiO 2 nanospheres (Cu–Co@SiO 2 ) have been successfully synthesized via a one-pot synthetic route in a reverse micelle system and characterized by SEM, TEM, EDS, XPS, PXRD, ICP, and N 2 adsorption–desorption methods. In each core–shell Cu–Co@SiO 2 nanosphere, several Cu–Co NPs are separately embedded in SiO 2 . Compared with their monometallic counterparts, the bimetallic core–shell nanospheres Cu x Co 1– x @SiO 2 with different metal compositions show a higher catalytic performance for hydrogen generation from the hydrolysis of ammonia borane (NH 3 BH 3, AB) at room temperature, due to the strain and ligand effects on the modification of the surface electronic structure and chemical properties of Cu–Co NPs in the SiO 2 nanospheres. Especially, the Cu 0.5 Co 0.5 @SiO 2 nanospheres show the best catalytic performance among all the synthesized Cu x Co 1– x @SiO 2 catalysts in the hydrolytic dehydrogenation of AB. In addition, the activation energy ( E a ) of Cu 0.5 Co 0.5 @SiO 2 core–shell structured nanospheres for the hydrolysis of AB is estimated to be 24 ± 2 kJ mol –1, relatively low values among the bimetallic catalysts reported for the same reaction. Furthermore, the multi-recycle test shows that the bimetallic Cu 0.5 Co 0.5 @SiO 2 core–shell nanospheres are still highly active for hydrolytic dehydrogenation of AB even after 10 runs, implying a good recycling stability in the catalytic reaction.