CATALYST FOR HYDROGEN GENERATION FROM SMALL ORGANIC MOLECULES

• US 20110059378A1
• Filed: 08/25/2010
• Published: 03/10/2011
• Est. Priority Date: 09/10/2009
• Status: Active Grant

• Current Assignee: University of Hong Kong (Government of Hong Kong Special Administrative Region)
• Original Assignee: University of Hong Kong (Government of Hong Kong Special Administrative Region)
• Inventors: Chan, Kwong Yu, Ting, Siu Wa, Tsang, Kwok Ying, Cheng, Shaoan, Van Der Laak, Nicole Kathleen
• Granted Patent: US 8,754,000 B2
• Time in Patent Office: Days
• US Class Current: 429/420
• CPC Class Codes: B01J 21/063 Titanium; Oxides or hydroxides thereof
• CPC Class Codes: B01J 21/08 Silica
• CPC Class Codes: B01J 21/18 Carbon
• CPC Class Codes: B01J 23/002 Mixed oxides other than spinels, e.g. perovskite
• CPC Class Codes: B01J 2523/00 Constitutive chemical elements of heterogeneous catalysts
• CPC Class Codes: B01J 2523/54 Bismuth
• CPC Class Codes: B01J 2523/821 Ruthenium
• CPC Class Codes: B01J 2523/828 Platinum
• CPC Class Codes: B01J 37/009 Preparation by separation, e.g. by filtration, decantation, screening
• CPC Class Codes: B01J 37/0203 the impregnation liquid containing organic compounds
• CPC Class Codes: B01J 37/0205 in several steps
• CPC Class Codes: B01J 37/0207 Pretreatment of the support
• CPC Class Codes: B01J 37/0211 using a colloidal suspension
• CPC Class Codes: C01B 2203/066 with fuel cells
• CPC Class Codes: C01B 2203/1064 Platinum group metal catalysts
• CPC Class Codes: C01B 2203/107 Platinum catalysts
• CPC Class Codes: C01B 2203/1211 Organic compounds or organic mixtures used in the process for making hydrogen or synthesis gas
• CPC Class Codes: C01B 2203/1223 Methanol
• CPC Class Codes: C01B 3/16 using catalysts
• CPC Class Codes: C01B 3/22 by decomposition of gaseous or liquid organic compounds C01B3/0005 takes precedence ; coking liquid carbonaceous materials C10B55/00
• CPC Class Codes: H01M 8/0612 : from carbon-containing material
• CPC Class Codes: H01M 8/0631 : Reactor construction specially adapted for combination reactor/fuel cell hydrogen C01B3/00; reactors for physicochemical processes B01J19/00
• CPC Class Codes: Y02E 60/50 : Fuel cells
• CPC Class Codes: Y02P 20/52 : using catalysts, e.g. selective catalysts

Abstract

A catalyst for the generation of hydrogen from a small organic molecule comprises a tertiary metal composition where: the first metal is either Pt or Ru; the second metal is at least one of Pt, Ru, Au, Pd, Rh, Ir, Os, and/or Re; and Bi, primarily present in the form of an oxide or of a mixture of oxides and carbonates and in the +3 oxidation state. A portion of the first and/or second metal may be in the form of an oxide. The catalyst can be in the form of a nanoparticle and supported on an inert substrate, such as carbon. The catalyst can be used for dehydrogenation of formic acid or other small organic molecules in a liquid state at ambient pressures and at temperatures below the boiling point of the liquid. The liquid can be an aqueous solution of the small organic molecule.

Claims

1. A catalyst for the dehydrogenation of a small organic molecule in a liquid state comprising:

a first metal comprising Pt or Ru;

at least one second metal comprising Pt, Ru, Au, Pd, Rh, Ir, Os, and/or Re; and

Bi, wherein said Bi is present primarily as an oxide or as a mixture of oxides and carbonates, and wherein a portion of at least one of said first or said second metals may be present as an oxide.

2. The catalyst of claim 1, wherein said Bi is present in at least 0.03 to 70 atom percent and is in an oxidation state of +3.

3. The catalyst of claim 1, wherein said first metal is Pt and said second metal is Ru.

4. The catalyst of claim 1, wherein said catalyst is Pt_aRu_bBi_cO_x where a is 0.3 to 6.5, b is 1, c is 0.1 to 6.4, and x is 0.15 to 9.6.

5. The catalyst of claim 1, wherein said catalyst is in the form of a nanoparticle.

6. The catalyst of claim 5, wherein said nanoparticle is 2 to 100 nm in cross section.

7. The catalyst of claim 1, wherein said catalyst further comprises a supporting material.

8. The catalyst of claim 7, wherein said supporting material comprises carbon, titania, alumina, or silica.

9. The catalyst of claim 7, wherein said supporting material comprises activated carbon, carbon black, carbon nanotubes or carbon nanorods.

10. A method of generating H₂ comprising:

providing a catalyst according to claim 1; and

contacting said catalyst with a liquid comprising a small organic molecule, wherein said small organic molecule is converted to H₂ and CO₂.

11. The method of claim 10, wherein said catalyst is insoluble in said liquid.

12. The method of claim 10, wherein said small organic molecule comprises formic acid, methanol, acetic acid, formaldehyde, or ethyl formate.

13. The method of claim 10, wherein said liquid comprises an aqueous solution of formic acid, wherein said formic acid is 0.1 to 100% v/v.

14. The method of claim 13, wherein said formic acid is an intermediate in the water gas shift reaction.

15. The method of claim 10, wherein said catalyst resides in a fixed bed reactor or a stirred tank reactor.

16. The method of claim 10, wherein contacting comprises continuously feeding said liquid to said catalyst.

17. The method of claim 10, wherein contacting occurs at a temperature from normal room temperature to above 140°

C.

18. A method of generating power comprising:

generating H₂ by a method according to claim 10;

separating said H₂ from CO₂; and

delivering said H₂ to a fuel cell, wherein H₂ and an oxidizer generate water and an electrical current.

19. The method of claim 18, wherein said generating, separating, and delivering are carried out in a portable device.