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 on 07/06/2026. Claims 1-3 and 5-20 are pending in the current Office action. Claim 4 was cancelled by Applicant. Claims 1-3, 9-15, and 18-20 were amended by Applicant.
Status of the Rejection
The rejections of claims 2, 9-13, 15, and 18-20 under 35 U.S.C. § 112(b) are withdrawn in view of Applicant’s amendments.
The rejections of claims 1-3 and 5-20 under 35 U.S.C. § 103 are withdrawn in view of Applicant’s amendments.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
Applicant has explicitly clarified the limitation “a potential vs. RHE of -0.2 V or less” requires potentials of -0.2 V vs. RHE or potentials more negative than -0.2 V vs. RHE (see Remarks p. 6, filed 07/06/2026).
List of Abbreviations
FE – Faradaic/Coulombic Efficiency
SHE – Standard Hydrogen Electrode
SS – Stainless Steel
RHE – Reversible Hydrogen Electrode
Claim Rejections - 35 USC § 102
Claims 14 and 16-17 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Liu (CN 113637989 A).
Regarding claim 14, Liu teaches a process for converting nitrate to ammonia (title) comprising:
electrochemically converting nitrate in the presence of a catalyst to form a product comprising ammonia (abstract and e.g., para. 7);
wherein the catalyst comprises cobalt (“The electrocatalyst used in this method is a metal-metal oxide, … The metal-metal oxide is selected from … cobalt-cobalt oxide, cobalt-cobalt tetroxide, …” para. 7) in a form of a gauze, sponge, or combination thereof (“the metal-metal oxide is in a foam-like state” para. 12 and see Fig. 1)1.
Regarding claim 16, Liu anticipates the limitations of claim 14, as described above.
Liu further teaches the catalyst does not comprise a support (“the metal-metal oxide itself serves as the cathode” para. 12).
Regarding claim 17, Liu anticipates the limitations of claim 14, as described above.
Liu further teaches the nitrate is present in a composition comprising KNO3 (“the electrolyte was an aqueous solution of 0.5 mmol/L potassium nitrate.” para. 46).
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, 5, 9, and 12-13 are rejected under 35 U.S.C. 103 as being unpatentable over Xiang (CN 113737205 A).
Regarding claim 1, Xiang teaches a process for converting nitrate to ammonia (title), comprising:
electrochemically converting nitrate in the presence of a catalyst to form a product comprising ammonia (“direct electrochemical reduction of nitrite to ammonia,” para. 1 and “a catalytic material supported on its surface,” para. 9);
wherein the catalyst comprises cobalt (the catalytic material is at least one of the following: … preferably, the elemental metal is selected from at least one of copper, cobalt, iron, nickel, gold, silver, platinum, or palladium …” para. 12) on a support (“catalytic material supported on its surface” para. 9 and “Ag-Cu/stainless steel wire mesh as an example” para. 23).
Xiang does not, in a single embodiment, teach the catalyst is cobalt and the support comprises a stainless steel (SS) in a form selected from the group consisting of a foil, mesh, cloth, gauze, sponge, and combinations thereof, and wherein
when the support is in the form of a mesh, cloth, gauze, or combinations thereof, the support has a mesh count of from 100 to 1000 per inch.
However, Xiang further teaches the support may comprise an SS mesh having a mesh count of 1000 per inch, a value within the claimed range (“Clean commercial 1000 mesh stainless steel wire mesh” para. 25).
As Xiang teaches a method for the electrocatalytic reduction of nitrate to ammonia, Xiang 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 Xiang, such that the support for the cobalt catalyst comprises an SS mesh having a mesh count of 1000 per inch, a value within the claimed range. A person having ordinary skill in the art would have been motivated to make this modification because Xiang explicitly suggests using such an SS mesh as the support.
Regarding claim 5, Xiang further teaches the cobalt is deposited on the support using chemical plating (para. 25 describes a chemical deposition process using sodium tartrate as a chemical reductant).
Regarding claim 9, Xiang renders the limitations of claim 1 obvious, as described above.
Xiang further teaches the ammonia producing current density is 83 mA/cm2, a value within the claimed range (“Constant current electrolysis was performed with a current density set at 100 mA/cm2 … The Faraday efficiency was 83%...” para. 44).
Regarding claim 12, Xiang renders the limitations of claim 1 obvious, as described above.
Xiang further teaches the coulombic efficiency for nitrate-to-ammonia conversion is 92%, a value within the claimed range (“the Faraday efficiency is 92%” para. 28).
Regarding claim 13, Xiang renders the limitations of claim 1 obvious, as described above.
Xiang does not report the coulombic efficiency for nitrate-to-nitrite conversion.
However, the instant specification indicates that a cobalt catalyst formed on a stainless steel substrate yields a coulombic efficiency for nitrate-to-nitrite conversion of 1.3-1.4% (Table 8) with a corresponding nitrate-to-ammonia conversion of 88-90%.
Therefore, because the method of Xiang employs a cobalt catalyst deposited on a stainless steel substrate and yields a coulombic efficiency for nitrate-to-ammonia conversion of 92% (“the Faraday efficiency is 92%” para. 28), it is considered that the method of Xiang necessarily yields a coulombic efficiency for nitrate-to-nitrite conversion of 2% or less.
Alternatively, because the method of Xiang employs a cobalt catalyst deposited on a stainless steel substrate and yields a coulombic efficiency for nitrate-to-ammonia conversion of 92% (“the Faraday efficiency is 92%” para. 28), it is considered that a person having ordinary skill in the art would have found it obvious the method of Xiang yields a coulombic efficiency for nitrate-to-nitrite conversion of 2% or less.
Claim 2 is rejected under 35 U.S.C. 103 as being unpatentable over Xiang, as applied to claim 1, and further in view of Botte (US Pat. Pub. 2009/0095636 A1).
Regarding claim 2, Xiang does not teach the catalyst has a cobalt loading of from 0.75 mg/cm2 to 25 mg/cm2.
Xiang instead teaches the catalyst loading as a thickness (“coating thickness to be about 20 µm” para. 25), which cannot be directly converted to units of mass per area.
However, Botte teaches a catalyst loading of about 2.5 mg/cm2, a value within each of the claimed ranges, is a suitable catalyst loading for the electrochemical production of ammonia (“4 cm2-metallic substrates … electroplated with 10±0.1 mg of Ni” para. 16).
As Botte teaches electrocatalyst loadings suitable for use in the electrochemical production of ammonia, Botte 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 Xiang, such that the catalyst has a cobalt loading of 2.5 mg/cm2, as taught by Botte. A person having ordinary skill in the art would have been motivated to make this modification because Botte teaches this is a suitable loading for an electrocatalyst configured to generate ammonia. Simple substitution of one known element for another (i.e., the catalyst loading of Botte in place of the catalyst loading of Xiang) to achieve predictable results establishes a prima facie case of obviousness (MPEP § 2143(I)(B)).
Claims 3, 6-8, 10-11, and 13 are rejected under 35 U.S.C. 103 as being unpatentable over Xiang, as applied to claims 1 or 5, and further in view of He et al. (“Splicing the active phases of copper/cobalt-based catalysts achieves high-rate tandem electroreduction of nitrate to ammonia” Nature Communications 13 (2022) 1129 and SI).
Regarding claim 3, Xiang renders the limitations of claim 1 obvious, as described above.
Xiang does not explicitly teach the support further comprises a metal selected from the group consisting of nickel, copper, a Ni-Cu alloy, titanium, and combinations thereof.
However, He teaches a method for electrochemically reducing nitrate to ammonia (title), wherein a copper substrate enhances the catalytic activity of a cobalt catalyst (e.g., “This core–shell arrangement of the Cu-based phases and Co-based phases, together with the rich phase interface between them, is the key to achieve a near-unity selectivity for subsequent NO3--to-NH3 catalysis on CuCoSP. The Cu foil substrate of CuCoSP may play a similar role to the Cu-based phases (Fig. 1a)” p. 4 col. 1 para. 2, “the Cu foil and inner Cu-based phases of CuCoSP can catalyze the preferential formation of NO2-, which might then be further reduced to NH3 at the outer Co-based phases” p. 4 col. 2 para. 1, and Fig. 1).
As He teaches a method for electrochemically reducing nitrate to ammonia, He 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 Xiang, such that the support further comprises copper, as taught by He. A person having ordinary skill in the art would have been motivated to make this modification because He teaches including copper as the support provides the predictable benefit of enhancing the catalytic activity of cobalt catalysts for nitrate to ammonia 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 6, Xiang renders the limitations of claim 5 obvious, as described above.
Xiang does not teach the cobalt is deposited on the support using a method comprising electroplating.
However, He teaches that electroplating (e.g., “we electrodeposited a hybrid of Cu–Co metals and alloy” p. 7 col. 1 para. 2) is a suitable method for depositing an electrocatalyst on a support for the electrochemical reduction of nitrate to ammonia (title).
As He teaches a method for electrochemically reducing nitrate to ammonia, He 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 Xiang, such that the cobalt is deposited on the support using a method comprising electroplating, as taught by He. A person having ordinary skill in the art would have been motivated to make this modification because He teaches electroplating is a suitable method for depositing a catalyst on a support for the electrochemical reduction of nitrate to ammonia. Simple substitution of one known element for another to achieve predictable results establishes a prima facie case of obviousness (MPEP § 2143(I)(B)).
Regarding claims 7 and 8, Xiang renders the limitations of claim 1 obvious, as described above.
Xiang does not teach the nitrate is present in a composition comprising KOH, KNO3, or a combination thereof (claim 7), or both KOH and KNO3 (claim 8).
Xiang instead teaches the nitrate is present in a composition comprising NaNO3 and NaNO3 (para. 28).
However, the composition of Xiang differs from the claimed composition only in the identity of the alkali metal used as the counterion to the nitrate anion i.e., Na+ rather than K+. Due to the close structural similarity between the claimed compositions, it is considered that a person having ordinary skill in the art would have found it obvious to modify the method of Xiang by substituting KNO3 and KOH in place of NaNO3 and NaOH. Close structural similarity between claimed chemical compositions establishes a prima facie case of obviousness (MPEP § 2144.09).
Furthermore, He teaches that a mixture of KNO3 and KOH (“0.01M KNO3 and 0.1M KOH (pH 13)” p. 4 col. 1 para. 3) is suitable for the electrolytic reduction of nitrate to ammonia (title).
As He teaches a method for electrochemically reducing nitrate to ammonia, He 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 Xiang, such that the nitrate is present as KNO3 and KOH in place of NaNO3 and NaOH, as taught by He. A person having ordinary skill in the art would have been motivated to make this modification because He teaches a mixture of KNO3 and KOH is suitable as the nitrate source in the electrochemical reduction of nitrate to ammonia. Simple substitution of one known element for another to achieve predictable results establishes a prima facie case of obviousness (MPEP § 2143(I)(B)). Furthermore, use of a material known in the art as suitable for a purpose establishes a prima facie case of obviousness (MPEP § 2144.07).
Regarding claims 10 and 11, Xiang renders the limitations of claim 1 obvious, as described above.
Xiang does not teach the process is conducted at a potential vs. RHE of from -0.2 V to -2 V (claim 10) or -0.2 V or less (claim 11).
However, He teaches that an applied potential of about 0 to about -0.3 V vs. RHE (Fig. 2f), a range overlapping the claimed ranges, is suitable for the electrolytic reduction of nitrate to ammonia (title).
As He teaches a method for electrochemically reducing nitrate to ammonia, He 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 Xiang by using an applied potential between about 0 and about -0.3 V vs. RHE, a range overlapping the claimed ranges, as taught by He. A person having ordinary skill in the art would have been motivated to make this modification because He teaches this voltage range is suitable for electrochemically reducing nitrate to ammonia. Simple substitution of one known element for another (i.e., the voltage range of He in place of the voltage range of Xiang) to achieve predictable results 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(I)).
Regarding claim 13, Xiang renders the limitations of claim 1 obvious, as described above.
Xiang does not report the coulombic efficiency for nitrate-to-nitrite conversion.
However, the instant specification indicates that a cobalt catalyst formed on a stainless steel substrate yields a coulombic efficiency for nitrate-to-nitrite conversion of 1.3-1.4% (Table 8) with a corresponding nitrate-to-ammonia conversion of 88-90%.
Therefore, because Xiang teaches the method employs a cobalt catalyst and a stainless steel substrate, and yields a coulombic efficiency for nitrate-to-ammonia conversion of 92% (“the Faraday efficiency is 92%” para. 28), it is considered that the method of Xiang necessarily yields a coulombic efficiency for nitrate-to-nitrite conversion of 2% or less.
Alternatively, because Xiang teaches the method employs a cobalt catalyst and a stainless steel substrate, and yields a coulombic efficiency for nitrate-to-ammonia conversion of 92% (“the Faraday efficiency is 92%” para. 28), it is considered that a person having ordinary skill in the art would have found it obvious the method of Xiang yields a coulombic efficiency for nitrate-to-nitrite conversion of 2% or less.
Alternatively, He teaches a method of electrochemically converting nitrate to ammonia (title), wherein a coulombic efficiency for nitrate-to-nitrite conversion is approximately 0% (Fig. 3b).
As He teaches a method for electrochemically reducing nitrate to ammonia, He 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 Xiang, such that the coulombic efficiency for nitrate-to-nitrite conversion is approximately 0%, as taught by He. A person having ordinary skill in the art would have been motivated to make this modification to achieve the predictable result of reducing the production of nitrite as a side product during the production of ammonia. Furthermore, combining prior art elements according to known methods to yield predictable results establishes a prima facie case of obviousness (MPEP § 2143(I)(A)).
Claims 15, 18, and 20 are rejected under 35 U.S.C. 103 as unpatentable over Liu (CN 113637989 A).
Regarding claim 15, Liu anticipate the limitations of claim 14, as described above in the rejection under 35 U.S.C. § 102(a)(1).
Liu does not teach the catalyst comprises 90% or greater cobalt.
However, Liu teaches the catalyst comprises from 5% to greater than 95% cobalt, a range overlapping the claimed range (“the mass content of the metal is 5% to 95%, and the mass content of the metal oxide is 95% to 5%.” para. 8). A range in the prior art overlapping a claimed range establishes a prima facie case of obviousness (MPEP § 2144.05(I)).
Furthermore, in a separate embodiment using copper, Liu teaches the catalyst comprises greater than 90% copper, a range encompassed by the claimed range (“a copper foam-copper oxide catalytic electrode, the content of copper oxide being controlled by the heating time. In this embodiment, heating is performed for 40 minutes, and copper oxide accounts for 10%.” para. 44)2.
As Liu teaches a method for the electrochemical reduction of nitrate to ammonia, Liu 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 Liu, such that the catalyst comprises 90% or greater cobalt, a range encompassed by the claimed range. A person having ordinary skill in the art would have been motivated to make this modification because Liu explicitly suggests using a catalyst composition comprising greater than 90% of the metal.
Regarding claim 18, Liu anticipate the limitations of claim 14, as described above in the rejection under 35 U.S.C. § 102(a)(1).
Liu does not explicitly teach the ammonia producing current density when the catalyst is cobalt gauze or sponge.
However, Liu further teaches the ammonia producing current density is between about 44 and 106 mA/cm2, a range within the claimed range (Figs. 16-17 show the total current density is between about 120 and 50 mA/cm2, and “the electrochemical ammonia production selectivity is 88.6%.” para. 67), when the catalyst is cobalt deposited on carbon cloth (Id.).
As Liu teaches a method for the electrochemical reduction of nitrate to ammonia, Liu 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 Liu, such that the ammonia producing current density is between about 44 and 106 mA/cm2, a range within the claimed range. A person having ordinary skill in the art would have been motivated to make this modification because Liu explicitly suggests using an ammonia producing current density between about 44 and 106 mA/cm2 for high surface area cobalt catalysts.
Regarding claim 20, Liu anticipate the limitations of claim 14, as described above in the rejection under 35 U.S.C. § 102(a)(1).
Liu does not explicitly teach the coulombic efficiency for nitrate-to-ammonia conversion when the catalyst is cobalt gauze or sponge.
However, Liu further teaches the coulombic efficiency for nitrate-to-ammonia conversion is 88.6%, a value within the claimed range (“the electrochemical ammonia production selectivity is 88.6%.” para. 67), when the catalyst is cobalt deposited on carbon cloth (Id.).
As Liu teaches a method for the electrochemical reduction of nitrate to ammonia, Liu is analogous art to the instant invention.
A person having ordinary skill in the art would therefore have found it obvious to modify the method Liu, such that the coulombic efficiency for nitrate-to-ammonia conversion is 88.6%, a value within the claimed range. A person having ordinary skill in the art would have been motivated to make this modification because Liu explicitly suggests using a coulombic efficiency for nitrate-to-ammonia conversion of 88.6% for high surface area cobalt catalysts.
Claim 19 is rejected under 35 U.S.C. 103 as being unpatentable over Liu (CN 113637989 A) in view of He et al. (“Splicing the active phases of copper/cobalt-based catalysts achieves high-rate tandem electroreduction of nitrate to ammonia” Nature Communications 13 (2022) 1129 and SI).
Regarding claim 19, Liu anticipate the limitations of claim 14, as described above in the rejection under 35 U.S.C. § 102(a)(1).
Liu does not teach the process is conducted at a potential vs. RHE of from -0.2 V to -2 V. Liu instead teaches the process is conducted at a potential vs. RHE of -0.15 V, a value close to the claimed range (“an applied voltage of -0.15V (vs RHE)” para. 67). A value in the prior art close to a claimed range establishes a prima facie case of obviousness (MPEP § 2144.05(I)).
Furthermore, He teaches that an applied potential of about 0 to about -0.3 V vs. RHE (Fig. 2f), a range overlapping the claimed range, is suitable for the electrolytic reduction of nitrate to ammonia (title).
As Liu and He each teach methods for electrochemically reducing nitrate to ammonia, Liu and He 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 Liu by using an applied potential between about 0 and about -0.3 V vs. RHE, a range overlapping the claimed range, as taught by He. A person having ordinary skill in the art would have been motivated to make this modification because He teaches this voltage range is suitable for electrochemically reducing nitrate to ammonia. Simple substitution of one known element for another (i.e., the voltage range of He in place of the voltage of Liu) to achieve predictable results 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(I)).
Response to Arguments
Applicant’s arguments, see Remarks p. 6, filed 07/06/2026, with respect to the rejections of claims 2, 9-13, 15, and 18-20 under 35 U.S.C. § 112(b) have been fully considered and are persuasive. The rejections of claims 2, 9-13, 15, and 18-20 under 35 U.S.C. § 112(b) have been withdrawn.
Applicant’s arguments, see Remarks p. 6-10 with respect to the rejections of claims 1-3 and 5-20 under 35 U.S.C. § 103 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
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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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Luan V. Van can be reached at (571)272-8521. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/ALEXANDER R. PARENT/ Examiner, Art Unit 1795
/LUAN V VAN/ Supervisory Patent Examiner, Art Unit 1795
1 Fig. 1 depicts an embodiment wherein the metal is copper (see para. 45), but is considered representative of what is meant by the term “foam-like state” i.e., a gauze or sponge.
2 I.e., 10% copper oxide, balance copper. Thus the catalyst comprises greater than 90% copper, because it comprises 90% pure copper and the copper oxide also comprises copper.
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