Ammonia decomposition catalyst systems

Patent metadata

Field	Value
Publication number	US-2024132348-A1
Application number	US-202318538049-A
Country	US
Kind code	A1
Filing date	Dec 13, 2023
Priority date	Aug 21, 2018
Publication date	Apr 25, 2024
Grant date	—

Abstract

In general, disclosed herein are methods for forming hydrogen by use of an ammonia decomposition catalyst system. For instance, a method can include contacting a catalyst system with an ammonia source at a temperature of about 450° C. or lower. The catalyst systems can include a support material and a trimetallic catalyst component carried on the support material and within a reactor. Disclosed catalyst systems can decompose ammonia at relatively low temperatures and can provide an efficient and cost-effective route to utilization of ammonia as a carbon-free hydrogen storage and generation material.

First claim

What is claimed is:

1 . A method for forming hydrogen, the method comprising:
contacting an ammonia decomposition catalyst system with an ammonia source at a reaction temperature of about 450° C. or lower to form hydrogen,
wherein the catalyst system comprising a support material and a trimetallic catalyst component carried on the support material and within a reactor, wherein the trimetallic catalyst component includes no more than three metals comprising a first metal being ruthenium, a second metal selected from the group consisting of magnesium, calcium, hafnium, scandium, rhenium, strontium, and yttrium, and a promoter comprising an alkali metal, wherein the ruthenium and the second metal are present in a weight ratio to one another of from about 8:1 to about 1:8, wherein the ruthenium is present in an amount of less than 4 wt. % of the catalyst system and the promoter is present in an amount of from about 5 wt. % to about 20 wt. % of the catalyst system, wherein the reactor is fluidly connected to the ammonia source such that ammonia flows from the ammonia source to the reactor;
a first heat exchanger located between the ammonia source and the reactor and configured to heat the ammonia; and
a hydrogen selective membrane fluidly connected to the catalyst system such that reaction product from the catalyst system.

2 . The method of claim 1 , further comprising a first heat exchanger located between the ammonia source and the reactor and configured to heat the ammonia.

3 . The method of claim 1 , wherein the promoter is a single metal selected from the group consisting of sodium, potassium, rubidium, and cesium.

4 . The method of claim 1 , wherein the support material comprises an inorganic oxide.

5 . The method of claim 1 , wherein the second metal is hafnium.

6 . The method of claim 1 , wherein the second metal is yttrium.

7 . The method of claim 1 , wherein the catalyst system comprises the promoter in an amount of from about 8 wt. % to about 15 wt. % of the catalyst system.

8 . The method of claim 1 , wherein the catalyst system comprises the ruthenium in an amount of 3 wt. % or less.

9 . The method of claim 1 , wherein the catalyst system comprises the ruthenium in an amount of 2 wt. % or less.

10 . The method of claim 1 , wherein the catalyst system comprises the ruthenium in an amount of 1 wt. % or less.

11 . The method of claim 1 , wherein the promoter is potassium.

12 . The method of claim 1 , wherein the method is carried out at a pressure of from about 1 bar to about 5 bar.

13 . The method of claim 1 , further comprising a hydrogen collection tank fluidly connected to a first side of the hydrogen selective membrane.

14 . The method of claim 1 , further comprising a fuel cell fluidly connected to a first side of the hydrogen selective membrane.

15 . The method of claim 1 , further comprising a second heat exchanger between the ammonia source and the reactor and configured to heat the ammonia.

Assignees

• Univ South Carolina

Inventors

• Mccullough Katherine
• Lauterbach Jochen

Classifications

• C01B2203/066

  with fuel cells · CPC title

• B01J23/462

  Ruthenium · CPC title

• C01B3/047 Primary

  Decomposition of ammonia · CPC title

• B01J8/009

  Membranes, e.g. feeding or removing reactants or products to or from the catalyst bed through a membrane · CPC title

• B01J19/2475

  Membrane reactors · CPC title