# US 2013/0153442 A1 · Regenerative gas sensor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0153442 A1 - Document ID: US20130153442A1 - Status: Published application - Kind: A1 - Application number: 13/328,558 - Filed: 2011-12-16 - Published: 2013-06-20 - Earliest claimed: 2011-12-16 - Assignees: UTC Fire & Security Corporation - Inventors: Lei Chen; Zhiwei Yang; Antonio M. Vincitore; Joseph J. Sangiovanni - Web page: https://patentgrep.com/patent/US20130153442A1 ## CPC - G01N 27/30: Electrodes, e.g. test electrodes; Half-cells (G01N27/414 takes precedence) - G01N 27/4045: {for gases other than oxygen} - G01N 27/407: for investigating or analysing gases {(G01N27/411 takes precedence)} - G01N 33/0044: {Sulphides, e.g. H2S} - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) ## Abstract A gas sensor includes a housing having disposed therein a membrane electrode assembly comprising a sensing electrode, a counter electrode, and a polymer membrane disposed between the sensing electrode and the counter electrode. The polymer membrane comprises an ionic liquid retained therein. The sensor also includes a catalyst support that can be stable in a range of potentials to allow for detection mode and catalyst regeneration mode to be operative. The sensor further includes a circuitry and algorithm to implement the catalyst regeneration mechanism electrochemically. The sensor further includes a chamber for reference gas to which the counter electrode is exposed, and a chamber for test gas to which a gas to be tested is exposed. The sensor also includes a pathway for test gas to enter the chamber and a measured electrical circuit connecting the sensing electrode and the counter electrode. ## Claims ### Claim 1 A gas sensor comprising: a housing; a membrane electrode assembly disposed in the housing, the membrane electrode assembly comprising a sensing electrode comprising a catalyst on a conductive support, a counter electrode comprising a catalyst on a conductive support, and a polymer membrane disposed between the sensing electrode and the counter electrode, wherein said polymer membrane includes an ionic liquid retained therein; said housing including a reference gas chamber to which the counter electrode is exposed, and a test gas chamber to which the sensing electrode is disposed; a pathway for test gas to enter the test gas chamber; a measurement electrical circuit connecting the sensing electrode and the counter electrode; an electrical circuit and algorithm for regenerating the catalyst when it is partially or completely deactivated by contaminants. ### Claim 2 (depends on 1) The sensor of claim 1, wherein said contaminants comprise sulfur. ### Claim 3 (depends on 1) The sensor of claim 1, wherein the conductive support comprises a conductive metal oxide or doped metal oxide. ### Claim 4 (depends on 1) The sensor of claim 1, wherein the conductive support comprises conductive carbon. ### Claim 5 (depends on 4) The gas sensor of claim 4, the sensor being free of a liquid water reservoir. ### Claim 6 (depends on 1) The gas sensor of claim 1, the sensor being free of a liquid water reservoir. ### Claim 7 (depends on 1) The sensor of claim 1, wherein the polymer membrane comprises an ionomer. ### Claim 8 (depends on 7) The sensor of claim 7, wherein the ionomer has a molecular structure that comprises a hydrophobic portion and a hydrophilic portion. ### Claim 9 (depends on 8) The sensor of claim 8, wherein the hydrophobic portion comprises a fluoropolymer repeat unit. ### Claim 10 (depends on 8) The sensor of claim 8, wherein the hydrophilic portion comprises a sulfonic acid group, a phosphonic acid group, or a sulfonamide acid group. ### Claim 11 (depends on 1) The sensor of claim 1, wherein the ionic liquid includes a cation or an anion that is grafted to the polymer. ### Claim 12 (depends on 1) The sensor of claim 1, wherein the ionic liquid comprises an imidazolium, pyridinium, tetralkylammonium, pyrrolidinium, trialkylsulfonium, pyrazolium, triazolium, thiazolium, oxazolium, pyridazinium, pyrimidinium, or pyrazinium cation. ### Claim 13 (depends on 1) The sensor of claim 1, wherein the ionic liquid comprises one or more cations according to the formula: wherein R and R1 are independently H, substituted or unsubstituted alkyl of 1 to 30 carbon atoms, or substituted or unsubstituted aryl of 6 to 30 carbon atoms; and X is an anion. ### Claim 14 (depends on 10) The sensor of claim 10, wherein R is selected from the group consisting of —(CH2)3CH3, —CH2CH3, —CH3, —CH═CH2, —CH2CN, and —(CH2)3CN, and R1 is selected from the group consisting of H, —CH3, —CH2CN, and —(CH2)3CN. ### Claim 15 (depends on 9) The sensor of claim 9, wherein the ionic liquid comprises one or more anions selected from the group consisting of Cl, Br, BF4, PF6, AlCl4, SCN, HSO4, HCO3, CH3SO3, CH3CH2SO4, (CH3(CH2)3O)2POO, (CF3SO2)2N, dicyanamide, CF3SO3, (CF3CF2SO2)2N, L-(+)-lactate, CH3SO4, and CH3COO. ### Claim 16 (depends on 1) The sensor of claim 1, wherein either or both of the sensing electrode has an ionic liquid retained within the electrode. ### Claim 17 A method of sensing a gas, comprising: generating a difference in electrochemical potential between a sensing electrode comprising a catalyst on a conductive support and a counter electrode comprising a catalyst on a conductive support, the sensing electrode and the counter electrode separated by a polymer membrane that includes an ionic liquid retained therein, wherein said difference in electrochemical potential is responsive to the presence and/or concentration of a component in a gas being tested; measuring voltage or current in an electrical circuit connecting the sensing electrode and the reference electrode, converting the measured voltage or current to a reading indicative of the presence and/or concentration of the component in the gas being tested; and periodically applying an electrical potential difference across the sensing electrode and the counter electrode to regenerate the catalyst when it is partially or completely deactivated by contaminants. ### Claim 18 (depends on 17) The method of claim 17, wherein said component is hydrogen sulfide and said contaminants comprise sulfur. ### Claim 19 (depends on 17) The method of claim 17, further comprising adjusting the conversion of measured voltage or current to the reading based on humidity. ### Claim 20 (depends on 19) The method of claim 19, wherein the conductive support comprises conductive carbon or metal oxides and the sensor is free of a liquid water reservoir.