Catalyst for thermochemical water splitting

Patent metadata

Field	Value
Publication number	US-2016243530-A1
Application number	US-201615144476-A
Country	US
Kind code	A1
Filing date	May 2, 2016
Priority date	Jul 25, 2012
Publication date	Aug 25, 2016
Grant date	—

Abstract

The present invention relates to a catalyst for the thermochemical generation of hydrogen from water and/or the thermochemical generation of carbon monoxide from carbon dioxide comprising a solid solution of cerium dioxide and uranium dioxide.

First claim

1 . A method for the generation of hydrogen from water and/or the generation of carbon monoxide from carbon dioxide comprising:
reducing at least part of a catalyst at a first elevated temperature to produce diatomic oxygen; contacting the catalyst with at least one of water and carbon dioxide at a second elevated temperature; and oxidising the at least partially reduced catalyst to generate the hydrogen and/or the carbon monoxide; wherein the second elevated temperature may be the same or different from the first elevated temperature; and wherein the catalyst comprises a solid solution of cerium dioxide and uranium dioxide.

2 . The method of claim 1 , wherein completion of oxidation of the catalyst is accomplished in less than 20 minutes.

3 . The method of claim 1 , wherein the catalyst further comprises zirconium dioxide.

4 . The method of claim 1 , wherein the catalyst consists essentially of cerium dioxide and uranium dioxide.

5 . The method of claim 1 , wherein the catalyst is free of zirconium dioxide.

6 . The method of claim 1 , wherein the catalyst was produced by dissolving a cerium salt, a uranium salt and optionally a zirconium salt in water; and then precipitating at a pH of at least 8 by addition of a base to form a precipitate, and calcining the precipitate.

7 . The method of claim 1 , wherein the second elevated temperature is lower than the first elevated temperature.

8 . The method of claim 1 , wherein the first elevated temperature is from 600° C. to 1200° C.

9 . The method of claim 1 , wherein the first elevated temperature is from 1000° C. to 1200° C.

10 . The method of claim 1 , wherein the second elevated temperature is from 600° C. to 1000° C.

11 . The method of claim 1 , wherein the second elevated temperature is from 600° C. to 900° C.

12 . The method of claim 1 , wherein the first and or second elevated temperature is obtained by heating using solar energy.

13 . The method of claim 1 , wherein a molar ratio of cerium and uranium is from 50 to 0.05.

14 . The method of claim 13 , wherein the molar ratio of cerium and uranium is from 10 to 0.1.

15 . The method of claim 1 , wherein the solid solution has a fluorite crystal structure.

16 . The method of claim 1 , wherein a total amount of cerium dioxide, uranium dioxide and optionally zirconium dioxide in the solid solution is at least 95.0 wt % based on the weight of the solid solution.

17 . The method of claim 16 , wherein the total amount of cerium dioxide, uranium dioxide and optionally zirconium dioxide in the solid solution is at least 99.0 wt % based on the weight of the solid solution.

18 . The method of claim 1 , wherein a molar ratio of cerium and uranium is from 10 to 1;
the solid solution has a fluorite crystal structure; a total amount of cerium dioxide and uranium dioxide in the solid solution is at least 99.0 wt %; and wherein the catalyst is free of zirconium dioxide.

19 . The method of claim 17 , wherein the catalyst consists essentially of cerium dioxide and uranium dioxide.

Assignees

• Saudi Basic Ind Corp

Inventors

• Idriss Hicham
• Al-Shankiti Ibraheam
• Choi Yong Man
• Al-Otaibi Fasia Mohammed

Classifications

• B01J35/70

  characterised by their crystalline properties, e.g. semi-crystalline (catalysts comprising carbon B01J21/18; molecular sieves B01J29/00) · CPC title

• B01J35/30

  characterised by their physical properties · CPC title

• B01J37/08

  Heat treatment {(B01J37/0009, B01J37/0018 take precedence)} · CPC title

• B01J37/031

  Precipitation · CPC title

• C01B3/063

  Cyclic methods · CPC title