Hollow porous-wall glass microspheres for hydrogen storage

Abstract

A hollow glass microsphere is provided having a diameter range of between 1 to 140 microns, a density of between 0.05 to 0.50 gm/cc, a porous-wall structure having wall openings defining an average pore size of between 10 to 1000 angstroms, and which contains therein a hydrogen storage material. The porous-wall structure facilitates the introduction of a hydrogen storage material into the interior of the hollow glass microsphere. Thereafter, a barrier coating may be applied and/or the microspheres are processed to alter or reduce the effective pore size. In this manner, the hollow glass microsphere can provide a membrane for the selective transport of hydrogen through the porous walls of the microsphere, the small pore size preventing gaseous or liquid contaminants from entering the interior of the hollow glass microsphere.

1 . A hydrogen storage apparatus comprising: 
 a hollow glass microsphere having a porous wall surrounding an internal volume; and,    a hydrogen storage material selected from the group consisting of palladium, alanates, chemical hydrides, and combinations thereof, positioned within said volume of said hollow glass microsphere.    
     
     
         2 . The hydrogen storage apparatus according to  claim 1  wherein said hollow glass microsphere has a density of between about 0.05 gm/cc to about 0.50 gm/cc.  
     
     
         3 . The hydrogen storage apparatus according to  claim 1  wherein said hollow glass microsphere has a diameter ranging from about 1.0 micron to about 140 microns.  
     
     
         4 . The hydrogen storage apparatus according to  claim 1  wherein said porous wall defines a plurality of openings having an average pore diameter of between about 10 angstroms to about 1000 angstroms.  
     
     
         5 . The hydrogen storage apparatus according to  claim 1  wherein said hollow glass microsphere additionally contains a porous coating on an exterior surface of said microsphere, said porous coating further defining a semipermeable membrane.  
     
     
         6 . The process of making a hydrogen storage apparatus comprising the steps of: 
 forming a hollow glass microsphere having an extractable phase;    removing said extractable phase, thereby providing a porous-wall structure permitting communication between an interior and an exterior of the hollow glass microsphere;    introducing into an interior of said hollow glass microsphere, a hydrogen storage material wherein said hydrogen storage apparatus can reversibly release and store hydrogen.    
     
     
         7 . The process according to  claim 6  comprising the additional step of providing a selectively permeable coating on an exterior surface of said microsphere.  
     
     
         8 . A process of providing a hydrogen storage apparatus comprising: 
 forming a porous hollow glass microsphere;    introducing through said pores a hydrogen storage material into an interior of said hollow glass microsphere; and,    thereafter treating said hollow glass microsphere so as to alter the pore properties.    
     
     
         9 . The process according to  claim 8  wherein said step of treating said pores of said hollow glass microspheres comprises a method selected from the group of methods consisting of providing a semi-permeable coating, providing a sol gel coating, heat treating said hollow glass microspheres, and combinations thereof.