Synthesis and hydrogen storage properties of novel metal hydrides

Abstract

The present disclosure relates to improved processes for the preparation of metal hydrides. The present disclosure also relates to metal hydrides, e.g., metal hydrides prepared by the processes described herein, that exhibit enhanced hydrogen storage capacity when used as hydrogen storage systems.

1 - 47 . (canceled) 
     
     
         48 . A metal hydride containing one or more transition metals selected from titanium, iron, cobalt, nickel, and copper, wherein
 (i) the metal hydride is stable as a bulk solid at room temperature;   (ii) the metal hydride is capable of absorbing and reversibly releasing hydrogen via a Kubas interaction;   (iii) the enthalpy of H 2  binding to the metal hydride is approximately thermodynamically neutral; and   (iv) the metal hydride optionally contains one or more organic groups, wherein when present, the one or more organic groups are bound to the metal center via a carbon atom in the organic group.   
     
     
         49 . The metal hydride according to  claim 48 , wherein the transition metal is titanium. 
     
     
         50 . The metal hydride according to  claim 48 , wherein the one or more transition metals are in more than one oxidation state. 
     
     
         51 . The metal hydride according to  claim 48 , wherein the surface area of the metal hydride is greater than about 2 m 2 /g. 
     
     
         52 . The metal hydride according to  claim 48 , wherein the surface area of the metal hydride is (i) about 10 m 2 /g or greater. 
     
     
         53 . The metal hydride according to  claim 48 , wherein the metal hydride is capable of absorbing hydrogen (H 2 ) in an amount of about 2% to about 14% based upon 100% total weight of the metal hydride without hydrogen stored in it. 
     
     
         54 . The metal hydride according to  claim 48 , further comprising one or more H 2  molecules coordinated to a metal center in the metal hydride. 
     
     
         55 . The metal hydride according to  claim 54 , wherein the interaction between the H 2  molecule(s) and a metal center in the metal hydride is a Kubas interaction. 
     
     
         56 . A metal hydride storage material comprising a metal hydride of  claim 48 , the metal hydride having sufficient microporosity to permit (i) H 2  to diffuse in and out of the material and the active binding sites of the metal hydride, (ii) the metal to coordinate with H 2  via a Kubas interaction, and (iii) absorption of H 2  in an amount of about 2.0% to about 14.0% (based upon 100% total weight of the metal hydride without hydrogen stored in it). 
     
     
         57 . The metal hydride according to  claim 48 , wherein the organic group, when present, is selected from alkyl, silylated alkyl, alkenyl, arylalkyl and aryl. 
     
     
         58 . The metal hydride according to  claim 57 , wherein the organic group, when present, is selected from bis(trimethylsilyl)methyl, trimethylsilylmethyl, mesityl, allyl, 1,3-dimethyl allyl, 1,3-diethyl allyl, optionally substituted benzyl, neopentyl, 2,2,2-dimethylphenyl propyl, phenyl, and combinations thereof. 
     
     
         59 . A composition comprising a metal hydride according to  claim 48 . 
     
     
         60 . A bulk solid comprising a metal hydride according to  claim 48 . 
     
     
         61 . A method of storing hydrogen comprising
 (i) providing a metal hydride according to  claim 48 ;   (ii) adding hydrogen to the metal hydride; and   (iii) allowing the hydrogen to coordinate to the metal hydride.   
     
     
         62 . A hydrogen storage system comprising a storage system and a metal hydride according to  claim 48  within the storage system. 
     
     
         63 . A battery or fuel cell comprising a metal hydride according to  claim 48 . 
     
     
         64 . A polymerization catalyst comprising a metal hydride according to  claim 48 . 
     
     
         65 . The polymerization catalyst according to  claim 64 , wherein the polymerization catalyst is an olefin polymerization catalyst. 
     
     
         66 . The polymerization catalyst according to  claim 65 , wherein the olefin is selected from the group consisting of ethylene, propylene, and combinations thereof. 
     
     
         67 . A method of storing hydrogen comprising
 (i) providing a metal hydride according to  claim 48 ;   (ii) adding hydrogen to the metal hydride; and   (iii) allowing the hydrogen to coordinate to the metal hydride.   
     
     
         68 . The method according to  claim 67 , further comprising releasing the hydrogen from the metal hydride. 
     
     
         69 . The method according to  claim 68 , wherein the hydrogen is released from the metal hydride by reducing the pressure of the hydrogen in the storage system or by increasing the temperature of the storage system. 
     
     
         70 . A process for preparing a metal hydride according to  claim 48 , the process comprising
 (i) heating an alkyl or aryl transition metal compound, or a combination thereof, in a solvent in the absence of hydrogen to form a precipitate;   (ii) optionally isolating the precipitate;   (iii) hydrogenating the precipitate; and   (iv) optionally isolating the hydrogenated precipitate.