Ultrafine Ru nanoparticles embedded in SiO2 nanospheres: Highly efficient catalysts for hydrolytic dehydrogenation of ammonia borane

Ru@SiO 2 core–shell structured nanospheres have been prepared via a one-pot synthetic route in a NP-5/cyclohexane reverse micelle system and characterized by XRD , SEM , TEM, N 2 adsorption–desorption, and H 2 temperature programmed desorption. The characterized results show that ultrafine Ru nanoparticles (NPs) of around 2 nm are effectively embedded in the center of well-proportioned spherical and porous silica nanospheres (∼25 nm in diameter). Interestingly, the number of Ru NPs increases inside the spherical particles of SiO 2 as the increase of Ru loading. The as-synthesized Ru@SiO 2 exhibits high catalytic activity and good durability for hydrogen generation from the aqueous of ammonia borane (AB) complex under ambient atmosphere at room temperature . The hydrolysis activation energy of Ru@SiO 2 was estimated to be about 38.2 kJ mol −1 , which is lower than most of the reported activation energy values for the same reaction using many different Ru-based and other noble metal containing catalysts, indicating the superior catalytic performance of these core–shell structured nanospheres.