# US 2014/0197045 A1 · Simultaneously quantifying an alkane and oxygen using a single sensor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0197045 A1 - Document ID: US20140197045A1 - Status: Published application - Kind: A1 - Application number: 14/218,817 - Filed: 2014-03-18 - Published: 2014-07-17 - Earliest claimed: 2012-08-28 - Assignees: Oakland University - Applicants: Oakland University - Inventors: Xiangqun Zeng; Zhe Wang - Web page: https://patentgrep.com/patent/US20140197045A1 ## CPC - C25B 3/00: Electrolytic production of organic compounds - C25B 3/01: Products - C25B 3/03: Acyclic or carbocyclic hydrocarbons - C25B 3/23: Oxidation (halogenation C25B3/27) - C25B 9/19: with diaphragms - C25B: ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR (anodic or cathodic protection C23F13/00; single-crystal growth C30B) ## Abstract An alkane gas is supplied to an interface between an activated surface of a platinum or palladium working electrode and an ionic liquid electrolyte. The alkane adsorbs at or near an interface complex formed at the interface. The ionic liquid electrolyte is selected from a group consisting of 1-ethyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-propyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1 -pentyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-hexyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1 -heptyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1 -octyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1 -nonyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, and 1-decyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imidem, and combinations thereof. While the alkane gas in the presence of oxygen is supplied to the interface, positive electrode potential is applied to the platinum or palladium working electrode, which causes oxidation of the adsorbed alkane to form a reaction product. A concentration of the alkane is quantified using an alkane anodic current or current density at the positive electrode potential. The alkane is used as an internal standard to calibrate oxygen detection. ## Claims ### Claim 1 A method for simultaneously quantifying an alkane and oxygen using a single sensor, the method comprising: supplying an alkane gas to an interface between an activated surface of a platinum or palladium working electrode and an ionic liquid electrolyte, whereby the alkane adsorbs at or near an interface complex formed at the interface, wherein the ionic liquid electrolyte is selected from a group consisting of 1-ethyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-propyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-pentyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-hexyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-heptyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-octyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, 1-nonyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, and 1-decyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imidem, and combinations thereof; supplying the alkane gas in the presence of oxygen to the interface; while the alkane gas in the presence of oxygen is supplied to the interface, applying a positive electrode potential to the platinum or palladium working electrode, thereby causing oxidation of the adsorbed alkane to form a reaction product; quantifying a concentration of the alkane using an alkane anodic current or an alkane anodic current density at the positive electrode potential; and using the alkane as an internal standard to calibrate oxygen detection. ### Claim 2 (depends on 1) The method as defined in claim 1 wherein prior to using the alkane as the internal standard, the method further includes applying a negative electrode potential to the platinum or palladium working electrode, thereby reducing the oxygen to form a reduced oxygen species. ### Claim 3 (depends on 2) The method as defined in claim 2, wherein prior to using the alkane as the internal standard and after applying the negative electrode potential, the method further comprises identifying an oxygen cathodic current or an oxygen cathodic current density at the negative electrode potential, the oxygen cathodic current or the oxygen cathodic current density being related to a square root of a concentration of the reaction product and the concentration of the reaction product being proportional to the alkane anodic current or the alkane anodic current density. ### Claim 4 (depends on 3) The method as defined in claim 3 wherein using the alkane as the internal standard includes: normalizing the oxygen cathodic current at the negative electrode potential using a square root of the alkane anodic current to generate a normalized oxygen cathodic current value; and calculating a concentration of the oxygen using the normalized oxygen cathodic current value and linear regression fitting. ### Claim 5 (depends on 3) The method as defined in claim 3 wherein using the alkane as the internal standard includes: normalizing the oxygen cathodic current density at the negative electrode potential using a square root of the alkane anodic current density to generate a normalized oxygen cathodic current density value; and calculating a concentration of the oxygen using the normalized oxygen cathodic current density value and linear regression fitting. ### Claim 6 (depends on 2) The method as defined in claim 2 wherein applying the positive electrode potential and applying the negative electrode potential is accomplished using chronoamperometry. ### Claim 7 (depends on 6) The method as defined in claim 6 wherein the chronoamperometry is accomplished using a double potential step method which includes: applying the positive electrode potential for a first predetermined amount of time; switching the positive electrode potential to the negative electrode potential; and applying the negative electrode potential for a second predetermined amount of time. ### Claim 8 (depends on 7) The method as defined in claim 7, further comprising: switching the negative electrode potential back to the positive electrode potential; and applying the positive electrode potential for a third predetermined amount of time. ### Claim 9 (depends on 7) The method as defined in claim 7 wherein: the electrode potentials are referenced to a quasi platinum reference electrode; the reaction product is carbon dioxide; the positive electrode potential is 0.9 V or a more positive electrode potential; and the negative electrode potential is −1.2 V or a more negative electrode potential. ### Claim 10 (depends on 2) The method as defined in claim 2 wherein the reduced oxygen species reacts with the reaction product of alkane oxidation to regenerate oxygen.