In-situ synthesized hollow nickel-silica spheres for hydrolytic dehydrogenation of ammonia borane

Abstract

) is able to hydrolyze at room temperature to generate hydrogen with high purity. For this feature, ammonia borane is expected as a hydrogen storage material for polymer membrane fuel cells for mobile use. It is reported that nickel-based catalyst is one of the highly active catalysts for this reaction [1-7]. Studies of catalysts for hydrogen generation from aqueous ammonia borane solution show that dispersion of active metals and/or amorphousness of active phase play important roles in the catalytic performances [1-7]. The morphological effect of nickel-silica catalyst was reported by comparing the activity between composite catalyst and supported catalyst [4]. In recent years, the fabrication and study of core-shell solid and hollow microspheres with well-defined structures have attracted substantial interest because of their potential applications in controlled drug delivery system, lightweight fillers, catalysis, chromatography, vessels for confined reactions, and photonic band gap material [8-13 ]. Sever al strategies have been developed, such as heterophase polymerization/combined with a sol-gel process [14, 15], emulsion/interfacial polymerization approach [1], spray-drying method [16 ], self 7assembly technique [18], surface living polymerization process [19], and the template -based route [20-23 ] to prepare hollow spheres comprising polymeric or ceramic materials. In this study, we firstly fabricat ion reported method of the highly active in-situ synthesized hollow nickel-silica composite spheres . By the method, the hollow nickel-silica composite spheres can be obtained in the simple way, and can be synthesized by sol-gel based method using L(+)-arginine as a promoter for the reaction to