纳米金属负载的ZIF-8复合材料制备与室温储氢性能

Fabrication and room-temperature hydrogen storage performances of nanoparticles-doped ZIF-8 composites

以纳米金属粒子(NPs)为溢流源,金属有机框架ZIF-8为受体,通过液相浸渍结合原位还原的方法制备了NPs@ZIF-8(NPs=Ni,NiPt或Pt)复合材料,并用X射线衍射仪、扫描电镜、透射电镜和气体吸附仪等仪器对产物进行了系统表征与研究.结果表明,纳米金属颗粒均匀地分散于ZIF-8载体中,金属粒子的负载并未改变ZIF-8的形貌和尺寸;相比于纯ZIF-8,该类复合材料在常温下表现出较好的储氢性能,这可归因于氢溢流机制和ZIF-8大的孔隙率;由于过渡金属不同的催化活性,3种复合材料的吸氢量大小顺序为:Pt@ZIF-8>NiPt@ZIF-8>Ni@ZIF-8.

In this paper,nanoparticles( NPs) as hydrogen dissociation source and metal-organic framework ZIF-8 as receptor were used to construct NPs@ ZIF-8( NPs = Ni,Ni Pt,Pt) composites by a facile liquid impregnation method followed by an in-situ reduction treatment. The final products have been characterized by X-ray diffractometer,scanning electron microscope,transmission electron microscope,gas adsorption instruments,and so on. The results showed that the metal NPs are dispersed uniformly into the framework of ZIF-8 and the incorporation of metal particles has not changed the morphology and particle size of ZIF-8 crystals. Importantly,these composites exhibited higher room-temperature hydrogen storage performances relative to pure ZIF-8 due to the spillover mechanism as well as the large porosity of ZIF-8. Furthermore,three composites showed the following trend in hydrogen adsorption amounts: Pt@ ZIF-8 > NiPt@ZIF-8 > Ni@ZIF-8,which can be ascribed to the different catalytic properties of transition metal NPs.