# US 10,479,693 B2 · Electro-thermochemical Li cycling for NH3 synthesis from N2 and H2O > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,479,693 B2 - Document ID: US10479693B2 - Status: Granted - Kind: B2 - Application number: 15/664,240 - Filed: 2017-07-31 - Published: 2018-02-01 - Granted: 2019-11-19 - Earliest claimed: 2016-08-01 - Assignees: The Board of Trustees of the Leland Stanford Junior University - Applicants: The Board of Trustees of the Leland Stanford Junior University - Inventors: Joshua M. McEnaney; John Schwalbe; Aayush Ranjan Singh; John Lin; Jakob Kibsgaard; Thomas F. Jaramillo; Matteo Cargnello; Jens K. Nørskov - Web page: https://patentgrep.com/patent/US10479693B2 ## CPC - C01C 1/04: Preparation of ammonia by synthesis (preparation or purification of gas mixtures for ammonia synthesis C01B3/025) - B01J 19/24: Stationary reactors without moving elements inside (B01J19/08, B01J19/26 take precedence; with stationary particles B01J8/02) - C25C 3/02: of alkali or alkaline earth metals - C25C 7/005: {of cells for the electrolysis of melts (C25C7/02 - C25C7/06 take precedence)} - C25C 7/06: Operating or servicing - B01J 2219/24: Stationary reactors without moving elements inside - C01C: AMMONIA; CYANOGEN; COMPOUNDS THEREOF ({metal hydrides, monoborane, diborane or addition complexes thereof C01B6/00}; salts of oxyacids of halogens C01B11/00; peroxides, salts of peroxyacids C01B15/00; thiosulfates, dithionites, polythionates C01B17/64; compounds containing selenium or tellurium C01B19/00; azides C01B21/08; {compounds other than ammonia or cyanogen, containing nitrogen, non-metals and optionally metals C01B21/082}; metal imides or amides C01B21/092; nitrites C01B21/50; {compounds of noble gases C01B23/0005}; phosphides C01B25/08; salts of oxyacids of phosphorus C01B25/16; compounds containing silicon C01B33/00; compounds containing boron C01B35/00) - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS - C25C: PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR ## Abstract An electro-thermochemical cycling system for producing ammonia is provided that includes a reaction chamber having a metal compound input port, an anode suitable for oxidation in contact with the metal compound and configured for oxidation of hydroxide ions to water and oxygen, a cathode suitable for plating in contact with the metal compound and configured to electrolyze the metal compound to metal, a voltage source connecting the cathode and anode, a nitrogen port to the reaction chamber that combines nitrogen with the electrolyzed metal on the cathode to form a metal-nitrogen compound proximal to the nitrogen input, an atomic hydrogen port to the reaction chamber that combines with the metal-nitrogen compound to form ammonia, and an ammonia output port from the reaction chamber, where a metal compound input port inputs the metal compound to the reaction chamber according to a depletion rate of the metal compound in the reaction chamber. ## Claims ### Claim 1 An electro-thermochemical cycling system for producing ammonia, comprising: a) a reaction chamber comprising a metal compound input port, wherein a metal compound is input to said reaction chamber through said metal compound input port; b) an anode and a cathode comprising an ON electrical state and an OFF electrical state, wherein said anode is in contact with said metal compound for oxidation of anions; c) a reactive metal formed on said cathode when said anode and said cathode are in said ON electrical state, wherein said cathode is in contact with said metal compound to reduce metal ions of said metal compound to form said reactive metal on said cathode, wherein said anode and said cathode are separated by a porous diffusion barrier disposed in said reaction chamber, wherein said porous diffusion barrier separates anodic products from said cathode and said reactive metal; d) a voltage source, wherein said voltage source connects said cathode to said anode to establish said electrical ON state and said electrical OFF state; e) a nitrogen port to said reaction chamber containing said electrolyzed reactive metal, wherein nitrogen from said nitrogen port combines with said electrolyzed reactive metal to form a metal-nitrogen compound proximal to said nitrogen input; f) an atomic hydrogen port to said reaction chamber containing said metal-nitrogen compound, wherein atomic hydrogen from said atomic hydrogen port combines with said metal-nitrogen compound to form ammonia; and g) an ammonia output port from said reaction chamber containing said ammonia, wherein said metal compound input port is configured to input said metal compound to said reaction chamber according to a depletion rate of said metal compound in said reaction chamber. ### Claim 2 (depends on 1) The electro-thermochemical cycling system for production of ammonia according to claim 1, wherein said metal compound comprises a metal selected from the group consisting of Li, Be, Mg, Na, Al, Zn, Ca, Sr, and Ba. ### Claim 3 (depends on 2) The electro-thermochemical cycling system for production of ammonia according to claim 2, wherein said porous diffusion barrier comprises a material selected from the group consisting of alumina, magnesia, and steel. ### Claim 4 (depends on 1) The electro-thermochemical cycling system for production of ammonia according to claim 1, wherein said reaction chamber is divided into separate reaction chambers that include said reaction chamber containing said electrolyzed metal, said reaction chamber containing said metal-nitrogen compound, and said reaction chamber containing said ammonia. ### Claim 5 (depends on 1) The electro-thermochemical cycling system for production of ammonia according to claim 1, wherein said cathode comprises a material selected from the group consisting of steel, Ni, Cu, Ti, Mo, and graphite. ### Claim 6 (depends on 1) The electro-thermochemical cycling system for production of ammonia according to claim 1, wherein said anode comprises a material selected from the group consisting of steel, Ni, Pt, W, metal alloys, metal oxides, and graphite. ### Claim 7 (depends on 1) The electro-thermochemical cycling system for production of ammonia according to claim 1, wherein said metal compound comprises a molten metal compound and an additive for reducing the melting point of said molten metal compound mixture, reducing the melting point of said molten metal compound and dissolving said metal compound, or dissolving said metal compound contained in said reaction chamber. ### Claim 8 (depends on 7) The electro-thermochemical cycling system for production of ammonia according to claim 7, wherein said additive comprises LiCl, KCl, CsCl, RbCl, LiI or alkali earth metal compounds for decreased melting point and removing hydrogen, oxygen, or hydroxide sources from said cathode, or removing hydrogen, oxygen, or hydroxide sources from said cathode. ### Claim 9 (depends on 1) The electro-thermochemical cycling system for production of ammonia according to claim 1, wherein said atomic hydrogen is selected from the group consisting of water, ethanol, hydrogen, and HCl. ### Claim 10 (depends on 1) The electro-thermochemical cycling system for production of ammonia according to claim 1, wherein anode oxidation source is selected from the group consisting of OH, Cl, Br, I, and F. ### Claim 11 (depends on 1) The electro-thermochemical cycling system for production of ammonia according to claim 1, wherein said reaction chamber comprises a cylindrical reaction chamber that is divided into three sub-chambers, wherein said anode and said cathode are separated by said diffusion barrier, wherein said three sub-chambers rotate about a central axis of said cylindrical reaction chamber, wherein said ammonia output port is positioned on a sidewall of said cylindrical reaction chamber.