Ammonia Decomposition Catalyst Systems

Patent metadata

Field	Value
Publication number	US-2020062590-A1
Application number	US-201916376158-A
Country	US
Kind code	A1
Filing date	Apr 5, 2019
Priority date	Aug 21, 2018
Publication date	Feb 27, 2020
Grant date	—

Abstract

Disclosed are ruthenium-based catalyst systems, hafnium-based catalyst systems, and yttrium-based catalyst systems for use in ammonia decomposition. Catalyst systems include ruthenium, hafnium, and/or yttrium optionally in combination with one or more additional metals that can be catalytic or catalyst promoters. Hafnium-based and yttrium-based catalyst systems can be free of ruthenium. The catalyst systems also include a support material. 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 . An ammonia decomposition reactor comprising:
an ammonia inlet; an ammonia decomposition catalyst system downstream of the ammonia inlet, the ammonia decomposition catalyst system comprising a support material and a catalyst component, the catalyst component comprising ruthenium and at least one additional metal that catalyzes and/or promotes ammonia decomposition; a hydrogen outlet downstream of the ammonia decomposition catalyst system; and a nitrogen outlet downstream of the ammonia decomposition catalyst system.

2 . The ammonia decomposition reactor of claim 1 , the catalyst system comprising the ruthenium in an amount of about 4 wt. % or less.

3 . The ammonia decomposition reactor of claim 1 , wherein the additional metal comprises an alkali metal, an alkaline earth metal, a transition metal, a metalloid, a post transition metal, or any combination thereof.

4 . The ammonia decomposition reactor of claim 1 , wherein the additional metal comprises potassium, sodium, magnesium, calcium, strontium, scandium, yttrium, titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, rhenium, iron, osmium, cobalt, rhodium, iridium, nickel, palladium, platinum, copper, silver, gold, zinc, cadmium, indium, tin, lead, lanthanum, bismuth, or any combination thereof.

5 . The ammonia decomposition reactor of claim 1 , wherein the catalyst component comprises a promoter.

6 . The ammonia decomposition reactor of claim 5 , wherein the catalyst promoter comprises sodium, potassium, rubidium, cesium, barium, or combinations thereof.

7 . The ammonia decomposition reactor of claim 1 , wherein the support material comprises an inorganic oxide.

8 . The ammonia decomposition reactor of claim 1 , further comprising a hydrogen selective membrane.

9 . An ammonia decomposition reactor comprising:
an ammonia inlet; an ammonia decomposition catalyst system downstream of the ammonia inlet, the ammonia decomposition catalyst system comprising a support material and a catalyst component, the catalyst component comprising hafnium and/or yttrium, wherein the catalyst system is free of ruthenium; a hydrogen outlet downstream of the ammonia decomposition catalyst system; and a nitrogen outlet downstream of the ammonia decomposition catalyst system.

10 . The ammonia decomposition reactor of claim 9 , the catalyst component comprising both hafnium and yttrium.

11 . The ammonia decomposition reactor of claim 9 , the catalyst component further comprising at least one additional metal.

12 . The ammonia decomposition reactor of claim 11 , wherein the additional metal comprises an alkali metal, an alkaline earth metal, a transition metal, a metalloid, indium, tin, lead, lanthanum, bismuth, or any combination thereof.

13 . The ammonia decomposition reactor of claim 9 , wherein the additional metal comprises potassium, sodium, magnesium, calcium, strontium, scandium, yttrium, titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, rhenium, iron, osmium, cobalt, rhodium, iridium, nickel, palladium, platinum, copper, silver, gold, zinc, cadmium, indium, tin, lead, lanthanum, bismuth, or any combination thereof.

14 . The ammonia decomposition reactor of claim 9 , wherein the catalyst component comprises a promoter.

15 . The ammonia decomposition reactor of claim 14 , wherein the promoter comprises sodium, potassium, rubidium, cesium, barium, or combinations thereof.

16 . The ammonia decomposition reactor of claim 9 , wherein the support material comprises an inorganic oxide.

17 . The ammonia decomposition reactor of claim 9 , further comprising a hydrogen selective membrane.

18 . A method for decomposing ammonia comprising contacting a catalyst system with ammonia at a reaction temperature of about 450° C. or lower to form hydrogen and nitrogen, the catalyst system comprising a support material and a ruthenium-based catalyst component, a yttrium-based catalyst component, or a hafnium-based catalyst component, the ruthenium-based catalyst component comprising ruthenium and at least one additional metal that catalyzes and/or promotes ammonia decomposition, the ruthenium and the additional metal being present in the catalyst in a weight ratio to one another of from about 1:9 to about 9:1, the yttrium-based catalyst component and the hafnium-based catalyst component being free of ruthenium.

19 . The method of claim 18 , the catalyst component further comprising a catalyst promoter.

20 . The method of claim 18 , wherein the catalyst component further comprises potassium, sodium, magnesium, calcium, strontium, scandium, yttrium, titanium, zirconium, hafnium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten, manganese, rhenium, iron, osmium, cobalt, rhodium, iridium, nickel, palladium, platinum, copper, silver, gold, zinc, cadmium, indium, tin, lead, lanthanum, bismuth, or any combination thereof.

21 . The method of claim 18 , wherein the method is carried out at a pressure of from about 1 bar to about 5 bar.

Assignees

• Univ South Carolina

Inventors

• Mccullough Katherine
• Lauterbach Jochen

Classifications

• C01B3/047 Primary

  Decomposition of ammonia · CPC title

• C01B2203/0405

  Purification by membrane separation · CPC title

• C01B2203/1082

  Composition of support materials · CPC title

• C01B2203/1047

  Group VIII metal catalysts · CPC title

• B01J2523/49

  Hafnium · CPC title