Influence of preparation conditions of hollow titania–nickel composite spheres on their catalytic activity for hydrolytic dehydrogenation of ammonia borane

The present work reports influence of preparation conditions of hollow titania–nickel composite spheres on their morphology and catalytic activity for hydrolytic dehydrogenation of ammonia borane (NH3BH3). The as-prepared hollow titania–nickel composite spheres were characterized by transmission electron microscopy (TEM). Catalytic activities of the hollow spheres for hydrolytic dehydrogenation of aqueous NaBH4/NH3BH3 solution improve with the decrease of Ti + Ni content. From the results of FTIR spectra and elemental analysis, the amount of residual polystyrene (PS) templates is able to be reduced by increasing aging time for the preparation, and the catalytic activity of the hollow spheres increases when the amount of residual PS templates decreases. The carbon content in the hollow spheres prepared with aging time = 24 h is 17.3 wt.%, and the evolution of 62 mL hydrogen is finished in about 22 min in the presence of the hollow spheres from aqueous NaBH4/NH3BH3 solution. The molar ratio of the hydrolytically generated hydrogen to the initial NH3BH3 in the presence of the hollow spheres is 2.7.