# US 8,771,635 B2 · Hydrogen release from complex metal hydrides by solvation in ionic liquids > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,771,635 B2 - Document ID: US8771635B2 - Status: Granted - Kind: B2 - Application number: 13/094,464 - Filed: 2011-04-26 - Published: 2011-11-17 - Granted: 2014-07-08 - Earliest claimed: 2010-04-26 - Assignees: Toyota Motor Engineering & Manufacturing North America, Inc. - Applicants: Rana F. Mohtadi; PremKumar Sivasubramanian - Inventors: Rana F. Mohtadi; PremKumar Sivasubramanian - Web page: https://patentgrep.com/patent/US8771635B2 ## CPC - C07D 233/54: having two double bonds between ring members or between ring members and non-ring members - C01B 3/065: by reaction of inorganic compounds with hydrides - Y02E 60/36: Hydrogen production from non-carbon containing sources, e.g. by water electrolysis - C07D: HETEROCYCLIC COMPOUNDS (macromolecular compounds C08) - C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C} - Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION ## Abstract A hydrogen release material includes a complex metal hydride and an ionic liquid wherein the hydrogen release material has a lower hydrogen release temperature in comparison to the complex metal hydride alone. Also disclosed is a process of releasing hydrogen from a storage material including the steps of: providing a complex metal hydride; combining the metal hydride with an ionic liquid in a desired amount forming a mixture; and heating the mixture to a temperature releasing hydrogen wherein the temperature is lower in comparison to the complex metal hydride alone. ## Claims ### Claim 1 A hydrogen release material comprising: a complex metal hydride; an ionic liquid wherein the hydrogen release material has a lower hydrogen release temperature in comparison to the complex metal hydride alone and wherein the ionic liquid includes a member selected from the group consisting of N,N′ imidazolium, N-pyridinium, pyridinium or pipperidinium cations with an anion including at least one of AlCl4−, Al2Cl7−, PF6−, BF4−, Cl− or CF3SO3−, and combinations thereof. ### Claim 2 (depends on 1) The hydrogen release material of claim 1 wherein the hydrogen release material has a faster hydrogen release rate in comparison to the complex metal hydride alone. ### Claim 3 (depends on 1) The hydrogen release material of claim 1 wherein the hydrogen release material has a more mobile and less stable complex hydride anion which lowers an activation barrier for hydrogen release in comparison to the complex metal hydride alone. ### Claim 4 (depends on 1) The hydrogen release material of claim 1 wherein the complex metal hydride has a formula of M(BH4)x where M is an alkali metal, an alkaline earth metal or a transition metal and 1≦x≦2. ### Claim 5 (depends on 1) The hydrogen release material of claim 1 wherein the complex metal hydride has a formula of M(AlH4)x where 1≦x≦2 and where M is an alkali metal, an alkaline earth metal or a transition metal. ### Claim 6 (depends on 1) The hydrogen release material of claim 1 wherein the complex metal hydride is selected from the group consisting of: magnesium borohydride, sodium borohydride, potassium borohydride, lithium borohydride and combinations thereof. ### Claim 7 (depends on 1) The hydrogen release material of claim 1 wherein the complex metal hydride cation is selected from the group consisting of: magnesium, calcium, strontium, barium, and mixtures thereof. ### Claim 8 (depends on 1) The hydrogen release material of claim 1 wherein the complex metal hydride has the formula M(AlH4)x, wherein M is an alkali metal, an alkaline earth metal or a transition metal and the complex metal hydride is selected from the group consisting of LiAlH4, NaAlH4, Mg(AlH4)2 and Ca(AlH4)2. ### Claim 9 (depends on 1) The hydrogen release material of claim 1 wherein the complex metal hydride is solubilized in the ionic liquid forming cations and anions. ### Claim 10 (depends on 1) The hydrogen release material of claim 1 wherein when a solid complex metal hydride when combined with a solid ionic liquid forms a paste or liquid at room temperature. ### Claim 11 (depends on 1) The hydrogen release material of claim 1 wherein the hydrogen release material is capable of reversible storage and release of hydrogen. ### Claim 12 (depends on 1) The hydrogen release material of claim 1 wherein the ionic liquid is present in an amount of 5 to 60 weight percent based on a total weight of a mixture. ### Claim 13 (depends on 1) The hydrogen release material of claim 1 wherein the combined ionic liquid and metal hydride form a liquid or a paste at room temperature. ### Claim 14 A process of releasing hydrogen from a storage material including the steps of: providing a complex metal hydride; combining the complex metal hydride with an ionic liquid in a desired amount forming a mixture, wherein the ionic liquid includes a member selected from the group consisting of N,N′ imidazolium, N-pyridinium, pyridinium or pipperidinium cations with an anion including at least one of AlCl4−, Al2Cl7−, PF6−, BF4−, Cl− or CF3SO3−, and combinations thereof; and heating the mixture to a temperature releasing hydrogen wherein the temperature is lower in comparison to the complex metal hydride alone. ### Claim 15 (depends on 14) The process of releasing hydrogen from a storage material of claim 14 including grinding the complex metal hydride. ### Claim 16 (depends on 14) The process of releasing hydrogen from a storage material of claim 14 wherein the combining step includes grinding the complex metal hydride and the ionic liquid. ### Claim 17 (depends on 16) The process of releasing hydrogen from a storage material of claim 16 wherein the ionic liquid melts followed by hydrogen release. ### Claim 18 (depends on 14) The process of releasing hydrogen from a storage material of claim 14 wherein the ionic liquid solubilizes the complex metal hydride lessening hydrogen reaction diffusion limitations of a solid complex metal hydride material. ### Claim 19 (depends on 14) The process of releasing hydrogen from a storage material of claim 14 wherein when a solid complex metal hydride when combined with a solid ionic liquid forms a paste or liquid at room temperature. ### Claim 20 (depends on 14) The process of releasing hydrogen from a storage material of claim 14 including a step of recharging the hydrogen release material with hydrogen after release. ### Claim 21 (depends on 20) The process of releasing hydrogen from a storage material of claim 20 wherein the recharging step occurs at a temperature and pressure lower than the complex metal hydride alone. ### Claim 22 (depends on 20) The process of releasing hydrogen from a storage material of claim 20 wherein the recharging step occurs faster in comparison to the complex metal hydride alone. ### Claim 23 (depends on 20) The process of releasing hydrogen from a storage material of claim 20 wherein the recharging step has a reduced activation barrier for hydrogen in comparison to the complex metal hydride alone. ### Claim 24 (depends on 20) The process of releasing hydrogen from a storage material of claim 20 including a step of drying the ionic liquid by removing water prior to combining with the metal hydride. ### Claim 25 (depends on 14) The process of claim 14 wherein the combined ionic liquid and metal hydride form a liquid or a paste at room temperature.