Catalysts containing red mud and rhodium for dry reforming

Patent metadata

Field	Value
Publication number	US-2023257264-A1
Application number	US-202217670606-A
Country	US
Kind code	A1
Filing date	Feb 14, 2022
Priority date	Feb 14, 2022
Publication date	Aug 17, 2023
Grant date	—

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 Rh2O3.

First claim

What is claimed is:

1 . A catalyst composition comprising:
about 50 wt % to about 99 wt % of a mixed-oxide material comprising iron oxide, aluminum oxide, and silicon oxide; and about 1 wt % to about 40 wt % of rhodium oxide, calculated as Rh 2 O 3 .

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 5 wt % to about 30 wt % of rhodium oxide.

8 . The catalyst composition of claim 1 , wherein the mixed-oxide material and the rhodium oxide comprise at least about 90 wt % of the catalyst composition.

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

10 . The catalyst composition of claim 1 , wherein a Brunauer-Emmett-Teller (BET) surface area of the catalyst composition is at least about 90 m 2 /g.

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

12 . 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.

13 . A method for preparing a catalyst composition, 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.

14 . The method of claim 13 , wherein the mixed-oxide material comprises red mud from a process for extracting alumina from bauxite.

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

16 . The method of claim 13 , wherein the acid comprises hydrochloric acid.

17 . The method of claim 13 , 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.

18 . The method of claim 13 , 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.

19 . The method of claim 18 , wherein the base is ammonia.

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

21 . The method of claim 18 , wherein the rhodium salt is rhodium acetylacetonate.

22 . The method of claim 13 , further comprising:
filtering the precursor composition; drying the filtered precursor composition; and calcining the dried precursor composition.

23 . The method of claim 13 , wherein calcining the precursor composition forms a catalyst composition comprising a BET surface area of at least about 90 m 2 /g.

24 . A method for dry reforming methane, the method comprising contacting methane and carbon dioxide with a catalyst composition comprising:
about 50 wt % to about 99 wt % of a mixed-oxide material comprising iron oxide, aluminum oxide, and silicon oxide; and about 1 wt % to about 40 wt % of rhodium oxide, calculated as Rh 2 O 3 ;
to form H 2 and CO.

25 . The method of claim 24 , wherein the catalyst composition comprises a BET surface area of at least about 90 m 2 /g.

26 . The method of claim 24 , wherein the mixed-oxide material comprises red mud from a process for extracting alumina from bauxite.

27 . The method of claim 24 , comprising contacting methane and carbon dioxide with the catalyst composition at a temperature of about 500° C. to about 1,000° C.

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

29 . The method of claim 24 , 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

• C01B3/40 Primary

  characterised by the catalyst · CPC title

• C01B2203/0238

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

• B01J35/613

  10-100 m2/g · CPC title

• B01J35/615

  100-500 m2/g · CPC title