Catalysts containing red mud and rhodium for dry reforming

Patent metadata

Field	Value
Publication number	US-12054389-B2
Application number	US-202217670606-A
Country	US
Kind code	B2
Filing date	Feb 14, 2022
Priority date	Feb 14, 2022
Publication date	Aug 6, 2024
Grant date	Aug 6, 2024

Abstract

Catalyst compositions containing red mud and rhodium are provided. An exemplary catalyst composition includes about 50 wt % to about 99 wt % of a mixed-oxide material including iron oxide, aluminum oxide, and silicon oxide, and about 1 wt % to about 40 wt % of rhodium oxide, calculated as Rh 2 O 3 .

First claim

What is claimed is:

1. A catalyst composition comprising:
about 50 wt. % to about 90 wt. % of a mixed-oxide material comprising iron oxide, aluminum oxide, and silicon oxide; and
about 10 wt % to about 40 wt % of rhodium oxide, calculated as Rh 2 O 3 ,

wherein a Brunauer-Emmett-Teller (BET) surface area of the catalyst composition is at least about 100 m 2 /g.

2. The catalyst composition of claim 1 , wherein the mixed-oxide material comprises:
about 5 wt % to about 60 wt % of iron oxide, calculated as Fe 2 O 3 ;
about 5 wt % to about 30 wt % of aluminum oxide, calculated as Al 2 O 3 ; and
about 3 wt % to about 50 wt % of silicon oxide, calculated as SiO 2 .

3. The catalyst composition of claim 1 , wherein the mixed-oxide material further comprises at least one of sodium oxide, calcium oxide, and titanium oxide.

4. The catalyst composition of claim 3 , wherein the mixed-oxide material comprises:
up to about 15 wt % of titanium oxide, calculated as TiO 2 ;
up to about 14 wt % of calcium oxide, calculated as CaO; and
up to about 10 wt % of sodium oxide, calculated as Na 2 O.

5. The catalyst composition of claim 1 , wherein the mixed-oxide material comprises:
about 30 wt % to about 60 wt % of iron oxide, calculated as Fe 2 O 3 ;
about 10 wt % to about 20 wt % of aluminum oxide, calculated as Al 2 O 3 ;
about 3 wt % to about 50 wt % of silicon oxide, calculated as SiO 2 ;
about 5 wt % to about 15 wt % of titanium oxide, calculated as TiO 2 ,
about 2 wt % to about 8 wt % of calcium oxide, calculated as CaO; and
about 2 wt % to about 10 wt % of sodium oxide, calculated as Na 2 O.

6. The catalyst composition of claim 1 , wherein the mixed-oxide material comprises red mud from a process for extracting alumina from bauxite.

7. The catalyst composition of claim 1 , comprising about 50 wt. % to about 85 wt. % of a mixed-oxide material comprising iron oxide, aluminum oxide, and silicon oxide; and about 15 wt % to about 30 wt. % of rhodium oxide.

8. The catalyst composition of claim 1 , wherein the rhodium oxide is supported on the mixed-oxide material.

9. The catalyst composition of claim 1 , wherein a BET surface area of the catalyst composition is at least about 125 m 2 /g.

10. The catalyst composition of claim 1 , wherein a BET surface area of the catalyst composition is about 125 m 2 /g to about 200 m 2 /g.

11. A method for preparing the catalyst composition of claim 1 , the method comprising:
contacting a mixed-oxide material comprising iron oxide, aluminum oxide, and silicon oxide with an acid to form an acid-treated support;
precipitating a mixture of the acid-treated support and rhodium to form a precursor composition; and
calcining the precursor composition to form the catalyst composition,

wherein the catalyst composition comprises:
about 50 wt. % to about 90 wt. % of a mixed-oxide material comprising iron oxide, aluminum oxide, and silicon oxide; and
about 10 wt % to about 40 wt % of rhodium oxide, calculated as Rh 2 O 3 , and

wherein a Brunauer-Emmett-Teller (BET) surface area of the catalyst composition is at least about 100 m 2 /g.

12. The method of claim 11 , wherein the mixed-oxide material comprises red mud from a process for extracting alumina from bauxite.

13. The method of claim 11 , wherein contacting the mixed-oxide material with an acid comprises adding the acid to an aqueous solution comprising the mixed-oxide material.

14. The method of claim 11 , wherein the acid comprises hydrochloric acid.

15. The method of claim 11 , wherein contacting the mixed-oxide material with acid forms an acid-treated support comprising a BET surface area of at least about 140 m 2 /g.

16. The method of claim 11 , wherein precipitating the mixture of the acid-treated support and rhodium comprises adding a base to an aqueous solution comprising the acid-treated support and a rhodium salt.

17. The method of claim 16 , wherein the base is ammonia.

18. The method of claim 16 , wherein adding the base to the aqueous solution increases the pH of the solution to greater than about 8.

19. The method of claim 16 , wherein the rhodium salt is rhodium acetylacetonate.

20. The method of claim 11 , further comprising:
filtering the precursor composition;
drying the filtered precursor composition; and
calcining the dried precursor composition.

21. A method for dry reforming methane, the method comprising contacting methane and carbon dioxide with the catalyst composition of claim 1 comprising:
about 50 wt. % to about 90 wt. % of a mixed-oxide material comprising iron oxide, aluminum oxide, and silicon oxide; and
about 10 wt % to about 40 wt % of rhodium oxide, calculated as Rh 2 O 3 ,
wherein a Brunauer-Emmett-Teller (BET) surface area of the catalyst composition is at least about 100 m 2 /g;

to form H 2 and CO.

22. The method of claim 21 , wherein the mixed-oxide material comprises red mud from a process for extracting alumina from bauxite.

23. The method of claim 21 , comprising contacting methane and carbon dioxide with the catalyst composition at a temperature of about 500° C. to about 1,000° C.

24. The method of claim 21 , comprising contacting methane and carbon dioxide with the catalyst composition at a pressure of about 5 bar to about 20 bar.

25. The method of claim 21 , comprising contacting methane and carbon dioxide with the catalyst composition at a gas hourly space velocity (GHSV) of about 1,000 h −1 to about 10,000 h −1 .

Assignees

• Saudi Arabian Oil Co

Inventors

• Albuali Mohammed A
• Alhajri Nawal Saad
• Arjah Samar
• Fadhel Bandar A
• Bamagain Rami

Classifications

• B01J2235/15

  X-ray diffraction · CPC title

• B01J35/615

  100-500 m2/g · CPC title

• B01J35/613

  10-100 m2/g · CPC title

• C01B2203/1064

  Platinum group metal catalysts · CPC title

• C01B2203/0238

  the reforming step being a carbon dioxide reforming step · CPC title