限域在介孔材料中的氨硼烷的催化脱氢性能和化学储氢性能(英文)

Catalytic Dehydrogenation of Ammonia Borane Confined in Mesoporous Materials for Chemical Hydrogen Storage

报道了同时采用催化剂和限域基体对氨硼烷(BH_3NH_3)脱氢性能的影响.结果发现,非贵金属催化剂和孔状限域基体能显著改变氨硼烷的储氢性能.填充在介孔二氧化硅中含Co催化剂的氨硼烷在75℃或90℃能释放出4%或9%纯氢,进一步用锂修饰介孔二氧化硅可使氨硼烷脱氢速度更快,但产生氢气、氨气和二硼烷的混合气.氨硼烷热分解活化能的降低导致填充在介孔二氧化硅中含催化剂的氨硼烷具有较快的动力学和热力学行为.

The simultaneous effect of catalyst and confinement substrate on the dehydrogenation properties of ammonia borane was presented. It was found that the hydrogen storage behavior for ammonia borane was remarkably altered by the presence of non-noble metal catalyst and confinement porous substrate. The Co catalyst- containing ammonia borane encapsulated in mesoporous silica can release up to 4, or 9 wt% pure hydrogen at isotherm temperature of 75 and 90℃. Further modification of mesoporous silica with lithium can result in even faster dehydrogenation of ammonia borane, but a mixture of hydrogen, ammonia and diborane is generated. The fast kinetics and thermodynamics of catalyst-doped ammonia borane in mesoporous silica is due to the significant decrease of the thermal decomposition activation energy for ammonia borane.