Ammonia synthesis catalyst, method for producing the same, and method for synthesizing ammonia using the same

Patent metadata

Field	Value
Publication number	US-2025375758-A1
Application number	US-202318875277-A
Country	US
Kind code	A1
Filing date	Jun 28, 2023
Priority date	Jun 28, 2022
Publication date	Dec 11, 2025
Grant date	—

Abstract

An ammonia synthesis catalyst including a catalyst support including cerium oxide and ruthenium supported on the catalyst support, wherein a peak pore diameter is in a range of 8 to 16 nm, and a pore volume in a pore diameter range of 10 to 16 nm is 0.10 cm 3 /g or more, and/or a pore volume in a pore diameter range of 8 to 20 nm is 0.16 cm 3 /g or more, as measured by a Barrett-Joyner-Halenda (BJH) method.

First claim

1 . An ammonia synthesis catalyst comprising a catalyst support including cerium oxide and ruthenium supported on the catalyst support,
wherein a peak pore diameter is in a range of 8 to 16 nm, and a pore volume in a pore diameter range of 10 to 16 nm is 0.10 cm 3 /g or more, and/or a pore volume in a pore diameter range of 8 to 20 nm is 0.16 cm 3 /g or more, as measured by a Barrett-Joyner-Halenda (BJH) method.

2 . The ammonia synthesis catalyst according to claim 1 , wherein a pore volume in a pore diameter range of 10 to 16 nm is 0.10 cm 3 /g or more, and a pore volume in a pore diameter range of 8 to 20 nm is 0.16 cm 3 /g or more, as measured by the BJH method.

3 . The ammonia synthesis catalyst according to claim 1 , wherein the catalyst support further contains at least one metal oxide selected from the group consisting of silicon oxide, zirconium oxide, magnesium oxide, lanthanum oxide, and aluminum oxide.

4 . The ammonia synthesis catalyst according to claim 1 , wherein an alkali metal is further supported on the catalyst support.

5 . A method for producing an ammonia synthesis catalyst, comprising the steps of:
obtaining a catalyst support by subjecting a catalyst support precursor including cerium oxide to heat treatment in a reducing atmosphere at 600 to 700° C. for 5 hours or more, wherein the catalyst support precursor has a peak pore diameter in a range of 4 to 16 nm and a pore volume in a pore diameter range of 4 to 16 nm of 0.16 cm 3 /g or more, as measured by a Barrett-Joyner-Halenda (BJH) method after calcination in air at 500° C. for 5 hours or more; and supporting ruthenium on the catalyst support.

6 . The method for producing an ammonia synthesis catalyst according to claim 5 , wherein the catalyst support precursor has a pore volume in a pore diameter range of 10 to 16 nm of less than 0.10 cm 3 /g and a pore volume in a pore diameter range of 8 to 20 nm of less than 0.16 cm 3 /g, as measured by the BJH method after calcination in air at 500° C. for 5 hours or more.

7 . The method for producing an ammonia synthesis catalyst according to claim 5 , wherein the heating temperature of the catalyst support precursor is 625 to 650° C.

8 . The method for producing an ammonia synthesis catalyst according to claim 5 , further comprising a step of preparing the catalyst support precursor by impregnating cerium oxide with a solution containing at least one metal compound selected from the group consisting of a silicon compound, a zirconium compound, a magnesium compound, a lanthanum compound, and an aluminum compound.

9 . The method for producing an ammonia synthesis catalyst according to claim 5 , further comprising supporting an alkali metal on the catalyst support.

10 . A method for synthesizing ammonia, comprising contacting a gas containing hydrogen and nitrogen with the ammonia synthesis catalyst according to claim 1 to synthesize ammonia.

11 . The ammonia synthesis catalyst according to claim 2 , wherein the catalyst support further contains at least one metal oxide selected from the group consisting of silicon oxide, zirconium oxide, magnesium oxide, lanthanum oxide, and aluminum oxide.

12 . The ammonia synthesis catalyst according to claim 2 , wherein an alkali metal is further supported on the catalyst support.

13 . The ammonia synthesis catalyst according to claim 3 , wherein an alkali metal is further supported on the catalyst support.

14 . The method for producing an ammonia synthesis catalyst according to claim 6 , wherein the heating temperature of the catalyst support precursor is 625 to 650° C.

15 . The method for producing an ammonia synthesis catalyst according to claim 6 , further comprising a step of preparing the catalyst support precursor by impregnating cerium oxide with a solution containing at least one metal compound selected from the group consisting of a silicon compound, a zirconium compound, a magnesium compound, a lanthanum compound, and an aluminum compound.

16 . The method for producing an ammonia synthesis catalyst according to claim 7 , further comprising a step of preparing the catalyst support precursor by impregnating cerium oxide with a solution containing at least one metal compound selected from the group consisting of a silicon compound, a zirconium compound, a magnesium compound, a lanthanum compound, and an aluminum compound.

17 . The method for producing an ammonia synthesis catalyst according to claim 6 , further comprising supporting an alkali metal on the catalyst support.

18 . The method for producing an ammonia synthesis catalyst according to claim 7 , further comprising supporting an alkali metal on the catalyst support.

19 . The method for producing an ammonia synthesis catalyst according to claim 8 , further comprising supporting an alkali metal on the catalyst support.

Assignees

• Toyota Chuo Kenkyusho Kk
• Toyota Motor Co Ltd
• Aist

Inventors

• Yamazaki Kiyoshi
• Goto Yoshihiro
• KIKUGAWA Masashi
• Ishikawa Marie
• Satou Akinori
• MANAKA Yuichi
• Nanba Tetsuya
• Matsumoto Hideyuki

Classifications

• B01J37/06

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

• B01J35/45

  Nanoparticles · CPC title

• B01J23/462

  Ruthenium · CPC title

• B01J37/0201

  Impregnation · CPC title

• B01J35/635

  0.5-1.0 ml/g · CPC title