Effect of salt addition on morphology and activity of in situ synthesized silica-ruthenium-nickel hollow sphere catalyst for hydrolysis of ammonia borane

["The present study investigated the effect of salt addition on morphology and activity of in situ synthesized silica-ruthenium-nickel hollow sphere catalyst for hydrolysis of ammonia borane. The in situ synthesized hollow sphere catalysts were prepared via the reduction of the precursors in the spherical particles in aqueous solution of ammonia borane with small amount of sodium borohydride. The synthetic method included the processes to parallelly occur the formation and activation of the hollow sphere catalysts. In the preparation of the spherical precursors, various amounts of a salt, sodium chloride, were added with the molar ratios of sodium to silicon (Na/Si) = 0-3.00, and the effect of its addition on morphology and activity for hydrolysis of ammonia borane of the hollow sphere catalysts were investigated. The results of SEM, TEM, and nitrogen sorption measurements revealed that the primary particle size decreased with increasing Na/Si ratios, and the samples with high integration of the primary particles and/or high dispersion of active ruthenium and nickel species in the silica-ruthenium-nickel particles formed uniform hollow spheres, and the hollow sphere catalyst exhibited high activity for hydrolysis of ammonia borane to generate hydrogen gas.","[GRAPHICS]","."]