Haber-bosch catalyst comprising an anion-vacant lattice

Patent metadata

Field	Value
Publication number	US-2021114005-A1
Application number	US-201917050313-A
Country	US
Kind code	A1
Filing date	Apr 24, 2019
Priority date	Apr 24, 2018
Publication date	Apr 22, 2021
Grant date	—

Abstract

A composition for catalysis of a Haber-Bosch process comprises an anion vacant lattice and a Haber-Bosch catalyst (e.g. Fe Ru). Suitable anion vacant lattices include oxynitrides and oxides, which may be doped or undoped, including CeaMbO2-XNY (Formula III) M is one or more elements with a valence lower than +4. “a” and “b” are independently in the range 0.05 to 0.95, with the proviso that “a” and “b” together sum to 1 (approximately). X is greater than 0 and less than 2. Y is greater than zero and less than or equal to X. A process employing the composition produces ammonia.

First claim

1 . A composition for catalysis of a Haber-Bosch process, the composition comprising an anion vacant lattice and a Haber-Bosch catalyst.

2 . The composition according to claim 1 , wherein the Haber-Bosch catalyst comprises a metal compound selected from the group consisting of: Fe, Co, Ni, Ru, or combinations thereof.

3 . (canceled)

4 . The composition according to claim 1 , wherein the anion vacant lattice is doped to promote anion vacancies.

5 . The composition according to claim 1 , wherein the anion vacant lattice is an oxynitride.

6 . The composition according to claim 5 , wherein the oxynitride is a compound according to formula III:
Ce a M b O 2-x N y    (Formula III)
wherein M is one or more elements with a valence lower than 4, “a” and “b” are independently in the range 0.05 to 0.95, with the proviso that “a” and “b” together sum to 1; 0<X<2; and 0<Y≤X.

7 . The composition according to claim 6 , wherein M is Sm and/or a is 0.5 to 0.9.

8 . The composition according to claim 6 , wherein (i) M is Pr or La; and/or (ii) a is 0.2 to 0.6.

9 . The composition according to claim 5 , wherein the oxynitride is a compound according to formula V or VI
Zr a M b O 2-x N y    (Formula V)
wherein M is titanium; and/or cerium; and or one or more elements with a valence lower than 4, “a” and “b” are independently in the range 0.05 to 0.95, with the proviso that “a” and “b” together sum to 1; 0<X<2; and 0<Y≤X
Ti a M b O 2-x N y    (Formula VI)

wherein M is zirconium; and/or cerium; and/or one or more elements with a valence lower than 4, “a” and “b” are independently in the range 0.05 to 0.95, with the proviso that “a” and “b” together sum to 1; 0<X<2; and 0<Y≤X.

10 . The composition according to claim 4 , wherein the anion vacant lattice is an oxygen vacant lattice and the oxygen vacant lattice comprises doped CeO 2 , doped ZrO 2 , doped TiO 2 , doped BaZrO 3 or combinations thereof.

11 . The composition according to claim 10 , wherein the oxygen vacant lattice is yttrium stabilized zirconia (YSZ).

12 . The composition according to claim 10 , wherein the oxygen vacant lattice is a compound according to formula II;
Ce a M b O 2-δ    (Formula II)
wherein, M is one or more elements with a valance of less than 4, “a” and “b” are independently in the range 0.05 to 0.95, with the proviso that “a” and “b” together sum to 1.

13 . The composition according to claim 12 , wherein (i) each of “a” and “b” are independently in the range 0.1 to 0.8 and/or (ii) M is Sm, Pr, La, Gd or combinations thereof.

14 . The composition according to claim 13 , wherein the oxygen vacant lattice comprises Ce 0.5 Sm 0.2 O 2-δ or Ce 0.5 Sm 0.5 O 2-δ .

15 . The composition according to claim 9 , wherein the oxygen vacant lattice is a compound according to formula I;
BaZr x Ce y Y z O 3-δ    (Formula I)
wherein, each of x, y and z are independently in the range 0.05 to 0.95, with the proviso that x, y and z together sum to 1.

16 . The composition according to claim 15 , wherein each of “x”, “y” and “z” are independently in the range 0.1 to 0.8.

17 . The composition according to claim 16 , wherein the oxygen vacant lattice comprises BaZr 0.1 Ce 0.7 Y 0.2 O 3-δ .

18 . (canceled)

19 . A process for producing ammonia, comprising the steps of:
i) providing a composition according to claim 1 ; and ii) exposing said composition to a mixture of nitrogen and hydrogen gas.

20 . The process of claim 19 , wherein the composition is exposed to a mixture of nitrogen and hydrogen at a temperature below 600° C. and a pressure below 20 MPa or the process is a batch process.

21 . (canceled)

22 . An anion vacant lattice according to formula III, V or VI:
Ce a M b O 2-X N Y    (Formula III)
wherein M is zirconium; and/or titanium and/or one or more elements with a valence lower than 4, “a” and “b” are independently in the range 0.05 to 0.95, with the proviso that “a” and “b” together sum to 1 (approximately); 0<X<2; and 0<Y≤X
Zr a M b O 2-X N Y    (Formula V)

wherein M is titanium; and/or cerium; and/or one or more elements with a valence lower than 4, “a” and “b” are independently in the range 0.05 to 0.95, with the proviso that “a” and “b” together sum to 1 (approximately); 0<X<2; and 0<Y≤X
Ti a M b O 2-X N Y    (Formula VI)

wherein M is zirconium; and/or cerium; and/or one or more elements with a valence lower than 4, “a” and “b” are independently in the range 0.05 to 0.95, with the proviso that “a” and “b” together sum to 1 (approximately); 0<X<2; and 0<Y≤X.

23 . The anion vacant lattice according to claim 22 , wherein (i) M is Sm, Pr and/or La; and (ii) a is from 0.1 to 0.9.

Assignees

• Univ Warwick

Inventors

• Tao Shanwen
• Humphreys John

Classifications

• B01J2235/15

  X-ray diffraction · CPC title

• B01J2235/30

  Scanning electron microscopy; Transmission electron microscopy · CPC title

• B01J35/733

  Perovskite-type · CPC title

• B01J2235/00

  Indexing scheme associated with group B01J35/00, related to the analysis techniques used to determine the catalysts form or properties · CPC title

• B01J37/036

  to form a gel or a cogel · CPC title