Cellular solid composite material comprising metal nanoparticles, preparation process and uses for the reversible storage of hydrogen

Patent metadata

Field	Value
Publication number	US-2016236177-A1
Application number	US-201415025764-A
Country	US
Kind code	A1
Filing date	Oct 2, 2014
Priority date	Oct 3, 2013
Publication date	Aug 18, 2016
Grant date	—

Abstract

A macroporous monolithic composite material to a carbon monolith is provided having a hierarchized porous structure has metal nanoparticles. The arrangement also includes a process for the preparation thereof, a process for storing hydrogen that uses same, and to a process for producing gaseous hydrogen that uses such a composite material, where the process is reversible.

First claim

1 . Cellular solid composite material that is in the form of a porous carbon monolith comprising:
a hierarchized porous network having macropores having a mean size d A of 1 μm to 100 μm and micropores having a mean size d 1 of 0.7 to 1.5 nm, said macropores and micropores being interconnected, said material having mesoporous network and and wherein said cellular solid composite material has nanoparticles of a metal M in the zero oxidation state, said metal M being selected from palladium and gold.

2 . Material according to claim 1 , wherein the nanoparticles of palladium or gold are present at the surface of the macropores of the monolith.

3 . Material according to claim 1 , wherein the size of the nanoparticles of metal M varies from 1 to 300 nm.

4 . Process for preparing a composite material as defined in claim 1 said process further comprising the following steps:
i) a step of impregnating a porous carbon monolith comprising a hierarchized porous network comprising macropores having a mean size d A of 1 μm to 100 μm and micropores having a mean size d 1 of 0.7 to 1.5 nm, said macropores and micropores being interconnected, said material having no mesoporous network, with a solution of a salt of a metal M selected from palladium and gold in a solvent;
ii) a step of air drying said monolith;
iii) a step of forming nanoparticles of said metal M in the zero oxidation state by heat treatment of said monolith at a temperature varying from 50 to 900° C., in the presence of a reducing gas, in order to reduce the metal ions M to the zero oxidation state.

5 . Process according to claim 4 , wherein the salt of a metal M is selected from palladium chloride, potassium tetrachloroaurate and hydrogen tetrachloroaurate.

6 . Process according to claim 4 , wherein the concentration of metal M salt within the impregnation solution varies from 10 −3 M to 1 M.

7 . Process according to claims 4 , wherein the heat treatment of step iii) is carried out in the presence of hydrogen at a temperature of 400° C. for 1 hour.

8 . Process for storing hydrogen in a composite material having nanoparticles of a metal M selected from palladium and gold in the zero oxidation state and as defined in claim 1 , said process at comprising least the following steps:
a) a step of degassing said material under high vacuum and at a temperature of 150 to 400° C.; b) a step of impregnating, at ambient temperature, said degassed material with a solution of at least one metal hydride of formula (I) X(BH 4 ) n with X=Li, Na, Mg or K, and n=1 when X=Li, Na or K and n=2 when X=Mg, in solution in an organic solvent selected from ethers; c) a step of drying the material impregnated with the metal hydride solution, said drying being carried out under low vacuum and at ambient temperature; and optionally d) the repetition, one or more times, of steps b) and c) above.

9 . Process according to claim 8 , wherein the degassing of the material during step a) is carried out at a temperature of 280 to 320° C.

10 . Process according to claim 8 , wherein the metal hydride of formula (I) is lithium borohydride.

11 . Process according to claim wherein the solvent of the metal hydride solution is methyl tert-butyl ether.

12 . Composite material that is in the storm of a porous carbon monolith having a hierarchized porous network comprising macropores having a mean size d A of 1 μm to 100 μm approximately and micropores having a mean size d 1 of 0.7 to 1.5 nm, said macropores and micropores being interconnected, said material having no mesoporous network, said composite material comprising:
nanoparticles of a metal M in the zero oxidation state, said metal M being selected from palladium and gold, and in that the micropores contain hydrogen in the form of a crystalline, semicrystalline or amorphous metal hydride selected from the hydrides of formula (I) X(BH 4 ) n with X=Li, Na, Mg or K, and n=1 when X=Li, Na or K and n=2 when X=Mg.

13 . Composite material according to claim 12 , wherein said site material's specific surface area is from 50 to 900 m 2 /g.

14 . Composite material according to claim 12 , wherein the volume of the micropores is greater than or equal to 0.30 cm 3 ·g −1 of composite monolith and in that the metal hydride is in amorphous form.

15 . Composite material as defined in claim 12 , wherein said composite material is suitable for the production of dihydrogen.

16 . Composite material as defined in claim 15 , wherein said composite material is suitable for supplying dihydrogen to a fuel cell operating with dihydrogen.

17 . Composite material as defined in claim 12 , wherein said composite material is subjected to a heating step at a temperature of at least 100° C. as part of said Dihydrogen production process.

18 . Composite material according to claim 17 , wherein the heating step is carried out at a temperature of 250 to 400° C.

19 . Reversible dihydrogen production process, comprising at least the following steps:
1) a dihydrogen production step during which a composite material as defined in claim 12 is subjected to a heating step at a temperature of at least 100° C., then 2) a rehydrogenation step during which said composite material is subjected to a hydrogen pressure of 50 to 200 bar at a temperature of 200 to 500° C. for 1 to 48 hours; and 3) the repetition of steps 1) and 2) above one or more times.

20 . Process according to claim 19 , wherein step 2) is carried out by subjecting the material to a hydrogen pressure of 100 bar at 400° C. for 12 to 24 hours.

Assignees

• Centre Nat Rech Scient
• Univ Pierre Et Marie Curie Paris 6

Inventors

• Backov Renal
• Gervais Christel
• Janot Raphael
• Sanchez Clement
• Depardieu Martin

Classifications

• Y02E60/32

  Hydrogen storage · CPC title

• B01J23/44

  Palladium · CPC title

• B01J35/1057

  Operations & Transport · mapped topic

• B01J21/18 Primary

  Carbon · CPC title

• B01J35/1076

  Operations & Transport · mapped topic