(485e) Functionalized Ordered Mesoporous Silica Composites As Potential Ammonia Storage Materials

Ammonia may provide an alternative energy supplier for its strong capability as hydrogen carrier. However, it is a problem that how to storage this kind of chemical at relatively high temperature, for example 300°C in fuel cell. In this work, a composite material based on metal halides and ordered mesoporous silica framework is developed and used to target ammonia at relatively high temperature. The silica framework is fabricated via evaporation induced self-assembly method and has tunable mesoporous structure with addition of hexadecyl trimethyl ammonium bromide (CTAB). Several metal salts at various concentrations are added to the mesoporous framework via wetness impregnation method. It is reported that ammonia storage capability is further enhanced by functionalization with relative metal sites. Along with capacity measurements, the incorporation of metal salts on mesoporous silica is studied using microscopy, X-ray diffraction and porosity characterization techniques. Results show that well-dispersed metal crystal trapped in submicron-sized porous structure can improve diffusion rate and increase pore accessibility while maintaining structural integrity at relatively high temperature. Capacity measurements show that functionalized metal/silica composite can work as potential materials for ammonia storage. It is also a thermal stable material for only 3% weight loss over 300°C.