DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Status of the Claims
This is a final Office action in response to Applicant’s amendments and remarks filed 06/24/2026. Claims 1-2, 4-5, 7-8, 10-12, and 15-25 are pending in the current Office action. Of these, claims 21-25 are withdrawn from consideration. Claims 1, 7, 17, and 21-22 were amended by Applicant.
Status of the Rejection
The objection to the specification is withdrawn in view of Applicant’s amendments.
The objections to claims 1 and 7 are withdrawn in view of Applicant’s amendments.
Applicant’s affirmation of the interpretation of the terms “physical solvent” and “chemical solvent” is acknowledged.
The rejections of claims 1-2, 4-5, 8, 10-12, and 15-20 under 35 U.S.C. § 112(b) are withdrawn in view of Applicant’s amendments.
The rejections of claims 1-2, 4-5, 7-8, 10-12, and 15-20 under 35 U.S.C. § 103 are withdrawn in view of Applicant’s amendments.
New grounds of rejection are necessitated by Applicant’s amendments.
Claim Interpretation
It will be noted that the term “physical solvent” is a term of art referring to solvents that dissolve acidic gases e.g., carbon dioxide, without undergoing a chemical change e.g., without forming an adduct.
Similarly, the term “chemical solvent” is a term of art referring to solvents that react with acidic gases when dissolved e.g., by forming an adduct.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1-2, 4-5, 8, 10-12, and 15-20 are rejected under 35 U.S.C. 103 as being unpatentable over Lakkaraju (US Pat. Pub. 2013/0008800) in view of De Kler (WO 2017/014635 A1) and Leonard (WO 2014/160529 A1).
Regarding claim 1, Lakkaraju teaches a method for electrochemically reducing carbon dioxide (abstract) comprising:
a) contacting a carbon dioxide-containing gas stream (“gas source 108” para. 27 and Fig. 1b) with a capture solvent (“carbon capture agent 124” Id.), thereby absorbing carbon dioxide from the carbon dioxide-containing gas stream to form a carbon dioxide-rich capture solvent (“The gas source 108 preferably includes a carbon dioxide source. … mixing chamber 132 generally facilitates the interaction between the carbon dioxide and the carbon capture agent 124 to permit the capture of carbon dioxide within the mixing chamber 132” Id.), wherein the capture solvent comprises a physical solvent, wherein the physical solvent is methanol (“the carbon dioxide capture agent 124 includes a non-aqueous, organic solvent. The organic solvent preferably includes one or more of methanol, …” para. 23);
b) introducing at least part of the carbon dioxide-rich capture solvent into a cathode compartment of an electrochemical cell (“The captured carbon dioxide may be introduced to the cathode compartment 114b for reduction of the captured carbon dioxide at the cathode 120” para. 27 and Fig. 1b);
c) applying an electrical potential between an anode and a cathode in the electrochemical cell sufficient for the cathode to reduce carbon dioxide into a reduced carbon dioxide product or product mixture in the carbon dioxide-rich capture solvent, thereby providing a carbon dioxide-poor capture solvent (“In the step 206, an electrical potential may be applied between the anode and the cathode sufficient for the cathode to reduce the carbamic zwitterion to a product mixture.” para. 33 and Fig. 2, see also para. 19 and Fig. 1b), wherein the cathode comprises one or more species selected from the group consisting of transition metals, post-transition metals, or alloys thereof (“the cathode 120 includes materials suitable for the reduction of carbon dioxide including cadmium, a cadmium alloy, cobalt, a cobalt alloy, nickel, a nickel alloy, chromium, a chromium alloy, indium, an indium alloy, iron, an iron alloy, copper, a copper alloy, lead, a lead alloy, palladium, a palladium alloy, platinum, a platinum alloy, molybdenum, a molybdenum alloy, tungsten, a tungsten alloy, niobium, a niobium alloy, silver, a silver alloy, tin, a tin alloy, rhodium, a rhodium alloy, ruthenium, a ruthenium alloy, carbon, and mixtures thereof” para. 20); and
d) collecting the reduced carbon dioxide product or product mixture (“The product extractor 110 generally facilitates extraction of one or more products from the electrolyte 122 and/or the carbon dioxide capture agent 124. …” para. 29 and Fig. 1b), wherein
the anode is separated from the cathode by a semi-permeable separator, thereby forming a cathodic compartment and an anodic compartment (“a separator (or membrane) 116” para. 20 and Fig. 1b and “The compartments may be separated by a … ion exchange membrane” para. 17).
Lakkaraju does not teach the absolute pressure in the electrochemical cell is 20 bar or more and 138 bar or less, or the absolute pressure of the carbon dioxide-containing gas stream is 20-200 bar.
However, De Kler teaches a method for electrochemically reducing carbon dioxide (title), wherein the electrochemical cell is operated at an absolute pressure between 20 and 200 bar (“The pressure in the electrochemical reactor is 20 bara or more, … Usually, the pressure in the electrochemical reactor will not exceed 200 bara” p. 13 line 28 – p. 14 line), a range encompassing the claimed range, and the absolute pressure of the carbon dioxide-containing gas stream is 20-200 bar (“The pressure of the carbon dioxide feed is preferably 20 bara or more, … Usually, the pressure of the carbon dioxide feed will not exceed 200 bara.” p. 11 lines 15-20), a range identical to the claimed range, which provides the predictable benefit of increasing the concentration of carbon dioxide at the cathode, thereby increasing the conversion efficiency of carbon dioxide to product (p. 6 line 27 – p. 7 line 2 and p. 21 lines 9-15).
As Lakkaraju and De Kler each teach methods for the electrochemical reduction of carbon dioxide, Lakkaraju and De Kler are analogous art to the instant invention.
It would therefore have been obvious to a person having ordinary skill in the art before the effective filing date of the instant application to modify the method of Lakkaraju, such that the absolute pressure in the electrochemical cell is 20 bar or more and 200 bar or less, a range encompassing the claimed range, and the absolute pressure of the carbon dioxide-containing gas stream is 20-200 bar, a range identical to the claimed range, as taught by De Kler. A person having ordinary skill in the art would have been motivated to make this modification to achieve the predictable benefit of increasing the concentration of carbon dioxide at the cathode, and thereby increasing the efficiency of carbon dioxide reduction to product, as taught by De Kler. Furthermore, combining prior art elements according to known methods to yield predictable results establishes a prima facie case of obviousness (MPEP § 2143(I)(A)). A range in the prior art overlapping a claimed range establishes a prima facie case of obviousness (MPEP § 2144.05).
Lakkaraju does not explicitly teach the transition metals, post-transition metals, and/or alloys thereof are in the form of a coating or a combination of coatings.
However, Leonard teaches a method for the electrochemical reduction of carbon dioxide (para. 45), wherein the cathode comprises a metal coating or a combination of coatings comprising the catalyst (“Cathode coatings on the cathode structure materials may be applied by electroplating, chemical vapor deposition (CVD) or other methods to all or various sections of the cathode structure. The cathode coatings may be metal or metal oxides, or converted to the metal or oxide by hydrogen reduction (metal oxide to metal) or thermal oxidation in air (formation of oxide coatings). The metals are the same group noted as the single metals or alloys specified. The coatings may include multiple coatings of different layers of materials for providing stability.” para. 82, see also paras. 66-81).
As Leonard teaches a method for the electrochemical reduction of carbon dioxide, Leonard is analogous art to the instant invention.
It would therefore have been obvious to a person having ordinary skill in the art before the effective filing date of the instant application to modify the cathode of Lakkaraju, such that the transition metals, post-transition metals, and/or alloys thereof are in the form of a coating or a combination of coatings, as taught by Leonard. A person having ordinary skill in the art would have been motivated to make this modification to reduce the amount of catalytic material needed in the system, and because Leonard teaches a coating is a suitable form for the catalytic material in a cathode for carbon dioxide reduction. Furthermore, combining prior art elements according to known methods to yield predictable results establishes a prima facie case of obviousness (MPEP § 2143(I)(A)).
Regarding claim 2, Lakkaraju further teaches e) recirculating at least part of the carbon dioxide-poor capture solvent to an absorber unit (“The carbon dioxide capture agent 124 may be recycled back into the compartment 114b for capture of additional carbon dioxide” para. 29 and Fig. 1b).
Regarding claim 4, modified Lakkaraju renders the limitations of claim 1 obvious, as described above.
Lakkaraju is silent as to the temperature in the electrochemical cell, which implies room temperature i.e., approximately 20 °C, a value within the claimed range.
Alternatively, De Kler further teaches the temperature of the cell is preferably between 0 and 20 °C (“The temperature in the electrochemical reactor during the method of the invention is preferably 20 °C or less … The temperature will normally not be below 0 °C” p. 15 lines 6-12), a range overlapping the claimed range.
It would therefore have been obvious to a person having ordinary skill in the art before the effective filing date of the instant application to modify the method of Lakkaraju, such that the temperature of the cell is between 0 and 20 °C, as taught by De Kler. A person having ordinary skill in the art would have been motivated to make this modification because De Kler teaches this temperature is suitable for the electrochemical reduction of carbon dioxide to products. Simple substitution of one known element for another (i.e., using the temperature range taught by De Kler in place of the unspecified temperature of Lakkaraju) to achieve predictable results (i.e., electrochemical reduction of carbon dioxide) establishes a prima facie case of obviousness (MPEP § 2143(I)(B)). A range in the prior art overlapping a claimed range establishes a prima facie case of obviousness (MPEP § 2144.05).
Regarding claim 5, modified Lakkaraju renders the limitations of claim 1 obvious, as described above.
Lakkaraju further teaches the carbon dioxide-containing gas stream of a) is contacted with the capture solvent in an absorber unit (“mixing chamber 132” para. 20 and Fig. 1b).
Lakkaraju does not explicitly teach the carbon dioxide is selectively absorbed by the capture solvent.
However, in an alternative embodiment Lakkaraju teaches the use of a capture solvent selective for carbon dioxide (“The carbon dioxide capture agent 124 may facilitate capture of carbon dioxide in the compartment 114b (or in the mixing chamber 132) by forming a carbamic zwitterion with the carbon dioxide.” para. 21).
It would therefore have been obvious to a person having ordinary skill in the art before the effective filing date of the instant application to modify the method of Lakkaraju, by using a capture solvent selective for carbon dioxide in addition to the physical solvent. A person having ordinary skill in the art would have been motivated to make this modification because Lakkaraju teaches solvents selective for carbon dioxide absorption are suitable for carbon dioxide reduction. Combining prior art elements according to known methods to yield predictable results establishes a prima facie case of obviousness (MPEP § 2143(I)(A)). Furthermore, use of a material known in the art as suitable for a purpose i.e., solvents having selectivity for carbon dioxide absorption, establishes a prima facie case of obviousness (MPEP § 2144.07).
Regarding claim 8, modified Lakkaraju renders the limitations of claim 1 obvious, as described above.
Lakkaraju further teaches the physical solvent is methanol (“the carbon dioxide capture agent 124 includes a non-aqueous, organic solvent. The organic solvent preferably includes one or more of methanol, …” para. 23).
Regarding claim 10, modified Lakkaraju renders the limitations of claim 1 obvious, as described above.
Lakkaraju does not teach the capture solvent comprises at least one chemical solvent.
However, in an alternative embodiment Lakkaraju teaches the use of a chemical solvent (“The carbon dioxide capture agent 124 may facilitate capture of carbon dioxide in the compartment 114b (or in the mixing chamber 132) by forming a carbamic zwitterion with the carbon dioxide.” para. 21).
It would therefore have been obvious to a person having ordinary skill in the art before the effective filing date of the instant application to modify the method of Lakkaraju, by using a chemical solvent in addition to the physical solvent. A person having ordinary skill in the art would have been motivated to make this modification because Lakkaraju teaches chemical solvents are suitable for carbon dioxide reduction. Combining prior art elements according to known methods to yield predictable results establishes a prima facie case of obviousness (MPEP § 2143(I)(A)). Furthermore, use of a material known in the art as suitable for a purpose i.e., chemical solvents, establishes a prima facie case of obviousness (MPEP § 2144.07).
Regarding claim 11, modified Lakkaraju, via Lakkaraju, further teaches the chemical solvent is a tertiary amine (“Preferred guanidine and pyrimidine derivatives include 1,1,3,3-tetramethylguanidine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-methyl-1,5, 7-triazabicyclo[4.4.0]dec-5-ene, 1,8-diazabicyclo[5.4.0]undec-7-ene, 1,5-diazabicyclo[4.3.0]non-5-ene, …” para. 21, note each of the listed preferred compounds, with the exception of 1,4,5,6-tetrahydropyrimidine, is a tertiary amine).
Regarding claim 12, modified Lakkaraju renders the limitations of claim 1 obvious, as described above.
Lakkaraju is silent as to the temperature of the contacting of carbon dioxide-containing gas stream with capture solvent, which implies room temperature i.e., approximately 20 °C, a value within the claimed range.
Alternatively, De Kler further teaches 20 °C, a value within the claimed range, is suitable as the temperature of the contacting of carbon dioxide-containing gas stream with capture solvent (p. 21 lines 16-22).
It would therefore have been obvious to a person having ordinary skill in the art before the effective filing date of the instant application to modify the method of Lakkaraju, such that the temperature of the contacting of carbon dioxide-containing gas stream with capture solvent is 20 °C, as taught by De Kler. A person having ordinary skill in the art would have been motivated to make this modification because De Kler teaches this temperature is suitable for contacting the carbon dioxide-containing gas stream with the capture solvent. Simple substitution of one known element for another (i.e., using the temperature taught by De Kler in place of the unspecified temperature of Lakkaraju) to achieve predictable results (i.e., mixing carbon dioxide with a capture solvent) establishes a prima facie case of obviousness (MPEP § 2143(I)(B)).
Regarding claim 15, modified Lakkaraju renders the limitations of claim 1 obvious, as described above.
Lakkaraju further teaches the reduced carbon dioxide product or product mixture comprises one or more selected from the group consisting of carbon monoxide, and carboxylic acids and salts thereof (“The organic product may include one or more of carbon monoxide, carbonate, and oxalate.” para. 23).
Regarding claim 16, modified Lakkaraju renders the limitations of claim 1 obvious, as described above.
Lakkaraju further teaches at least one salt in a non-aqueous solution is added to the cathodic compartment to improve electrical conductivity (“the cell 102 may include an electrolyte suitable for a non-aqueous solvent, preferably with a quarternary [sic] ammonium cation.” para. 23 and “An electrolyte solution 122 (e.g., anolyte or catholyte 122) may fill both compartments 114a-114b.” para. 20, see also Fig. 1b).
Regarding claim 17, modified Lakkaraju renders the limitations of claim 1 obvious, as described above.
Lakkaraju further teaches at least one salt in a non-aqueous solution is added to the anodic compartment to improve electrical conductivity (“the cell 102 may include an electrolyte suitable for a non-aqueous solvent, preferably with a quarternary [sic] ammonium cation.” para. 23 and “An electrolyte solution 122 (e.g., anolyte or catholyte 122) may fill both compartments 114a-114b.” para. 20, see also Fig. 1b. I.e., Lakkaraju teaches the electrolyte is added to both compartments).
Regarding claim 18, modified Lakkaraju renders the limitations of claim 1 obvious, as described above.
Lakkaraju further teaches at least one salt in an aqueous solution is added to the cathodic compartment to improve electrical conductivity (“An electrolyte solution 122 (e.g., anolyte or catholyte 122) may fill both compartments 114a-114b. The electrolyte solution 122 may include water as a solvent with water soluble salts for providing various cations and anions in solution,” para. 20 and Fig. 1b).
Regarding claim 19, modified Lakkaraju renders the limitations of claim 1 obvious, as described above.
Lakkaraju further teaches at least one salt in an aqueous solution is added to the anodic compartment to improve electrical conductivity (“An electrolyte solution 122 (e.g., anolyte or catholyte 122) may fill both compartments 114a-114b. The electrolyte solution 122 may include water as a solvent with water soluble salts for providing various cations and anions in solution,” para. 20 and Fig. 1b).
Regarding claim 20, modified Lakkaraju renders the limitations of claim 1 obvious, as described above.
Lakkaraju further teaches the cathode comprises an electrically conducting metal electrocatalyst (“the cathode 120 includes materials suitable for the reduction of carbon dioxide including cadmium, a cadmium alloy, cobalt, a cobalt alloy, nickel, a nickel alloy, chromium, a chromium alloy, indium, an indium alloy, iron, an iron alloy, copper, a copper alloy, lead, a lead alloy, palladium, a palladium alloy, platinum, a platinum alloy, molybdenum, a molybdenum alloy, tungsten, a tungsten alloy, niobium, a niobium alloy, silver, a silver alloy, tin, a tin alloy, rhodium, a rhodium alloy, ruthenium, a ruthenium alloy, carbon, and mixtures thereof.” para. 20).
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Lakkaraju in view of De Kler and Leonard, as applied to claim 1, above, and further in view of Yoon (US Pat. Pub. 2017/0072361 A1).
Regarding claim 7, modified Lakkaraju renders the limitations of claim 1 obvious, as described above.
Modified Lakkaraju does not teach the capture solvent is a mixture of diisopropylamine, water and one of tetrahydrothiophene or diethylamine; or dimethylethanolamine, water and one of tetrahydrothiophene or diethylamine.
However, Yoon teaches a carbon dioxide capture solvent composition suitable for use in an electrochemical cell (abstract), wherein the capture solvent comprises a mixture of water and amines (“an aqueous electrolyte solution group consisting of amines” para. 34), wherein the amines may comprise diethylamine and/or diisopropylamine (The secondary amines may include saturated aliphatic secondary amines such as dimethylamine, diethylamine, diisopropylamine, etc.,” para. 35).
As Yoon teaches a carbon dioxide capture solvent suitable for use in an electrochemical cell, Yoon is analogous art to the instant invention.
It would therefore have been obvious to a person having ordinary skill in the art before the effective filing date of the instant application to modify the method of Lakkaraju, such that the capture solvent comprises a mixture of water, diisopropylamine, and diethylamine. A person having ordinary skill in the art would have been motivated to make this modification because Yoon teaches a mixture of water and secondary amines is suitable for the absorption of carbon dioxide and its subsequent reaction in an electrochemical cell. Use of a material known in the art as suitable for a purpose establishes a prima facie case of obviousness (MPEP § 2144.07).
Response to Arguments
Applicant’s arguments, see Remarks p. 11, filed 06/24/2026, with respect to the objections to claims 1 and 7 have been fully considered and are persuasive. The objections to claims 1 and 7 have been withdrawn.
Applicant’s arguments, see Remarks p. 11, filed 06/24/2026, with respect to the rejections of claims 1-2, 4-5, 8, 10-12, and 15-20 under 35 U.S.C. § 112(b) have been fully considered and are persuasive. The rejections of claims 1-2, 4-5, 8, 10-12, and 15-20 have been withdrawn.
Applicant’s arguments, see Remarks p. 12, filed 06/24/2026, with respect to the rejections of claims 1-2, 4-5, 7-8, 10-12, and 15-20 under 35 U.S.C. § 103 have been fully considered and are persuasive. The rejections of claims 1-2, 4-5, 7-8, 10-12, and 15-20 have therefore been withdrawn.
Applicant’s Argument #1
Applicant argues on p. 11 that neither Lakkaraju, De Kler, nor Yoon teach the use of a cathode comprising a coating as claimed in amended claim 1, and that claim 1 is therefore allowable over the prior art.
Examiner’s Response #1
Examiner agrees in part. Examiner agrees that Lakkaraju and Yoon do not teach the use of a cathode comprising a coating as recited in amended claim 1. However, De Kler teaches the cathode is embedded in the ion exchange membrane (“the cathode and/or anode may be embedded in one of the ion exchange layers of the bipolar membrane.” p. 16 lines 8-12), and is therefore considered to read on the limitation “the cathode comprises a coating … comprising … ion-conductive polymers” as currently drafted in claim 1.
Furthermore, as described in the rejections, above, it is not considered that the cumulative limitations of claim 1, or those claims depending therefrom, are patentably distinguished over the prior art.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ALEXANDER R PARENT whose telephone number is (571)270-0948. The examiner can normally be reached M-F 11:00 AM - 6 PM EST.
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/ALEXANDER R. PARENT/Examiner, Art Unit 1795
/LUAN V VAN/Supervisory Patent Examiner, Art Unit 1795
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