Abstract:
A hydrogen storage composition based on a metal hydride dispersed in an aerogel prepared by a sol-gel process. The starting material for the aerogel is an organometallic compound, including the alkoxysilanes, organometals of the form M(OR)x and MOxRy, where R is an alkyl group of the form CnH2n+1, M is an oxide-forming metal, n, x, and y are integers, and y is two less than the valence of M. A sol is prepared by combining the starting material, alcohol, water, and an acid. The sol is conditioned to the proper viscosity and a hydride in the form of a fine powder is added. The mixture is polymerized and dried under supercritical conditions. The final product is a composition having a hydride uniformly dispersed throughout an inert, stable and highly porous matrix. It is capable of absorbing up to 30 moles of hydrogen per kilogram at room temperature and pressure, rapidly and reversibly. Hydrogen absorbed by the composition can be readily be recovered by heat or evacuation.
Abstract:
The present invention provides a process for eliminating halogen-containing compounds contained in a gas or a liquid, characterized in that the gas or liquid is brought into contact with a composition based on an alumina and/or a hydrated alumina and at least one compound (A) comprising at least one metallic element selected from metals from groups VIII, IB and/or IIB of the periodic table, and in that the total metallic element(s) content is at most 45% by weight with respect to the total composition weight, the complement by weight preferably comprising in a major part alumina and/or hydrated alumina.