KR-20260066818-A - ELECTROLYZER AND METHOD OF USE

Abstract

A reduction electrode layer comprising a carbon oxide reduction catalyst that promotes the reduction of carbon oxides; an oxidation electrode layer comprising a catalyst that promotes the oxidation of water; a polymer electrolyte membrane (PEM) layer disposed between the reduction electrode layer and the oxidation electrode layer in contact; and a membrane electrode assembly having a salt having a concentration of at least about 10 μM in at least a portion of the MEA are disclosed.

Inventors

• 케이브 에토샤 알.
• 마 시차오
• 젱 쿤
• 후네그나우 사라
• 쿨 켄드라 피.
• 레오나드 조지
• 미쉬라 애슐리 디.
• 카쉬 아제이 알.

Assignees

• 오푸스-12 인코포레이티드

Dates

Publication Date

20260512

Application Date

20191126

Priority Date

20181128

Claims (20)

1. As an electrochemical system configured to electrolytically reduce carbon oxides, (a) a membrane electrode assembly (MEA) comprising: (i) a reduction electrode layer comprising a carbon oxide reduction catalyst that promotes the reduction of carbon oxides; (ii) an oxidation electrode layer comprising a catalyst that promotes the oxidation of water; and (iii) a bipolar polymer electrolyte membrane (PEM) layer disposed between the reduction electrode layer and the oxidation electrode layer in contact with each other; and (b) a source of oxidation electrode water, wherein the source of oxidation electrode water is connected to the MEA in such a manner that the oxidation electrode water contacts the oxidation electrode layer and provides salt to the MEA; and (c) A recirculation loop connected to the MEA and configured to recover oxide electrode water from the MEA, store and/or process the recovered oxide electrode water, and supply the stored or processed oxide electrode water to the MEA. Includes, An electrochemical system comprising a bipolar PEM layer including at least one cation-conducting polymer layer, at least one anion-conducting polymer layer, and a bipolar interface between the cation-conducting polymer layer and the anion-conducting polymer layer, wherein the cation-conducting polymer layer is disposed between an oxidation electrode layer and an anion-conducting polymer layer.
2. In claim 1, the reduction electrode layer is an electrochemical system comprising an anion-conducting polymer.
3. In claim 1, the oxidation electrode layer comprises a cation-conducting polymer in an electrochemical system.
4. In paragraph 1, the salt is an electrochemical system containing alkali metal ions.
5. The electrochemical system according to claim 1, wherein the salt comprises an anion selected from the group consisting of phosphate, sulfate, carbonate, bicarbonate, and hydroxide.
6. An electrochemical system according to claim 1, wherein the carbon oxide reduction catalyst comprises copper, and the salt comprises (i) an alkali metal cation and (ii) a bicarbonate, sulfate, or hydroxide anion.
7. In claim 6, the electrochemical system in which the salt is present in the oxidation electrode water at a concentration of 10 μM to 1 M.
8. In claim 6, the electrochemical system in which the salt is present in the oxidation electrode water at a concentration of 1 mM to 50 mM.
9. An electrochemical system according to claim 1, wherein the carbon oxide reduction catalyst comprises gold, and the salt comprises (i) an alkali metal cation and (ii) a bicarbonate, hydroxide, or sulfate anion.
10. In claim 9, the electrochemical system in which the salt is present in the oxidation electrode water at a concentration of 10 μM to 200 mM.
11. In claim 9, the electrochemical system in which the salt is present in the oxidation electrode water at a concentration of 100 μM to 20 mM.
12. In paragraph 9, the MEA is an electrochemical system that substantially does not contain transition metal ions.
13. The electrochemical system according to claim 1, wherein the carbon oxide reduction catalyst comprises copper, and the salt comprises (i) an alkali metal cation and (ii) a bicarbonate or hydroxide anion.
14. In paragraph 13, the electrochemical system in which the salt is present in the oxidation electrode water at a concentration of 10 mM to 15 M.
15. In paragraph 13, the electrochemical system in which the salt is present in the oxidation electrode water at a concentration of 50 mM to 1 M.
16. In claim 1, the recirculation loop is an electrochemical system comprising a reservoir for storing oxidation electrode water.
17. In claim 1, the electrochemical system comprising a recirculation loop that includes an oxidation electrode water purification element configured to remove impurities from the oxidation electrode water.
18. An electrochemical system according to claim 1, further comprising a reduction electrode water conduit connected to a recirculation loop and configured to provide water recovered from the carbon oxide stream to the recirculation loop after the carbon oxide stream contacts the reduction electrode layer of the MEA.
19. An electrochemical system according to claim 18, further comprising a water separator connected to a reduction electrode water conduit and configured to separate the reduction electrode water from a carbon oxide stream.
20. In claim 1, the salt is an electrochemical system comprising (i) an alkali metal cation and (ii) a bicarbonate, sulfate, or hydroxide anion.

Description

Electrolyzer and Method of Use Cross-reference regarding related applications This application claims the benefit of U.S. provisional application serial number 62/772,460 filed on November 28, 2018, and U.S. provisional application serial number 62/939,960 filed on November 25, 2019, the entirety of which is incorporated herein by reference for all purposes. Statement of government support The present invention was made with government support under Award No. NNX17CJ02C awarded by NASA and Award No. DE-AR0000819 (ARPA-E) awarded by the Department of Energy. The government holds specific rights to the present invention. Technology field The present disclosure generally relates to the field of electrolytic carbon oxide reduction, and more specifically to a system and method for operating an electrolytic carbon oxide reactor. Electrolytic carbon dioxide reactors must balance various operating conditions, such as the reactant composition at the oxidation and reduction electrodes, the electrical energy delivered to the oxidation and reduction electrodes, and the electrolyte and the physicochemical environment of the oxidation and reduction electrodes. Balancing these conditions can strongly influence the operating voltage of the electrolytic reactor, the Faraday yield, and the mixing of products generated at the reduction electrode, including carbon monoxide (CO) and/or other carbon-containing products (CCPs) and hydrogen. The background and context descriptions included herein are generally provided solely for the purpose of presenting the context of the present disclosure. Much of the present disclosure represents the work of the inventors, and merely because such work is described in the background section or presented in context elsewhere in this document does not imply that such work is recognized as prior art. summation One aspect of the present disclosure relates to a membrane electrode assembly (MEA) that may be characterized by the following features: (a) a cathode layer comprising a carbon oxide reduction catalyst that promotes the reduction of carbon oxides; (b) an anode layer comprising a catalyst that promotes the oxidation of water; (c) a polymer electrolyte membrane (PEM) layer disposed between the cathode layer and the anode layer in contact with each other; and (d) salt ions of a salt solution in contact with the MEA, wherein the salt in the salt solution has a concentration of at least about 10 μM. The MEA in contact with the salt solution may have a concentration of a salt (or salt ions) different from the concentration of the salt in the salt solution. In some embodiments, the concentration of salt or salt ions in the MEA (taking into account multiple counterions donated by multivalent ions) is lower than the concentration of salt in the salt solution. In certain embodiments, the carbon oxide is carbon dioxide and the carbon oxide reduction catalyst comprises gold, silver, copper, or a combination thereof. In certain embodiments, the carbon oxide is carbon monoxide and the carbon oxide reduction catalyst comprises gold, silver, copper, or a combination thereof. In a specific embodiment, the reduction electrode layer comprises an anion-conducting polymer. In a specific embodiment, the oxidation electrode layer comprises a cation-conducting polymer. In certain embodiments, the MEA is bipolar, having at least one layer of a cation-conducting polymer and at least one layer of an anion-conducting polymer. In some embodiments, the PEM layer comprises a polymer electrolyte layer and a reduction electrode buffer layer. For example, the PEM layer may comprise a cation-conducting polymer and the reduction electrode buffer layer may comprise an anion-conducting polymer. In some cases, the PEM layer comprises an anion-conducting polymer. In certain embodiments, the salt ion comprises an alkali metal ion. In some cases, the salt ion comprises an anion selected from the group consisting of phosphates, sulfates, carbonates, bicarbonates, and hydroxides. In certain embodiments, the MEA is a bipolar MEA, and the carbon oxide reduction catalyst comprises copper. In some such cases, the salt comprises (i) an alkali metal cation and (ii) a bicarbonate, sulfate, or hydroxide anion. Such salt may be present in the salt solution at a concentration of about 1 mM to about 1 M, or about 1 mM to about 50 mM. In some cases, the bipolar MEA is configured to reduce carbon dioxide and/or carbon monoxide at the reduction electrode layer to produce methane, wherein the salt ion is a sodium ion. In some cases, the bipolar MEA is configured to reduce carbon dioxide and/or carbon monoxide at the reduction electrode layer to produce one or more organic compounds having two or more carbon atoms, wherein the salt ion includes ions of potassium, cesium, rubidium, or any combination thereof. In certain embodiments, the MEA is a bipolar MEA, wherein the carbon oxide reduction catalyst comprises gold, and the salt comprises (i) an alk