Ruthenium nanoparticles confined in SBA-15 as highly efficient catalyst for hydrolytic dehydrogenation of ammonia borane and hydrazine borane

摘要

Ultrafine ruthenium nanoparticles (NPs) within the mesopores of the SBA-15 have been successfully prepared by using a “double solvents” method, in which n -hexane is used as a hydrophobic solvent and RuCl₃ aqueous solution is used as a hydrophilic solvent. After the impregnation and reduction processes, the samples were characterized by XRD, TEM, EDX, XPS, N₂ adsorption-desorption, and ICP techniques. The TEM images show that small sized Ru NPs with an average size of 3.0?±?0.8?nm are uniformly dispersed in the mesopores of SBA-15. The as-synthesized Ru@SBA-15 nanocomposites (NCs) display exceptional catalytic activity for hydrogen generation by the hydrolysis of ammonia borane (NH₃BH₃, AB) and hydrazine borane (N₂H₄BH₃, HB) at room temperature with the turnover frequency (TOF) value of 316 and 706?mol H₂ (mol Ru min)?1, respectively, relatively high values reported so far for the same reaction. The activation energies ( E _a) for the hydrolysis of AB and HB catalyzed by Ru@SBA-15 NCs are measured to be 34.8?±?2 and 41.3?±?2?kJ mol?1, respectively. Moreover, Ru@SBA-15 NCs also show satisfied durable stability for the hydrolytic dehydrogenation of AB and HB, respectively.