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 .
List of Abbreviations
FE – Faradaic/Coulombic Efficiency
NF – Nickel Foam
NSA – Nanosheet Arrays
SCE – Saturated Calomel Electrode
SHE – Standard Hydrogen Electrode
RHE – Reversible Hydrogen Electrode
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
Claims 2, 4, 9-13, 15, and 18-20 are rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor regards as the invention.
Regarding claims 2, 4, 9-10, 12-13, 15, and 18-20, a broad range or limitation together with a narrow range or limitation that falls within the broad range or limitation (in the same claim) may be considered indefinite if the resulting claim does not clearly set forth the metes and bounds of the patent protection desired. See MPEP § 2173.05(c). In the present instance, claims 2, 4, 9-10, 12-13, 15, and 18-20 each recite a broad range e.g., “about 0.75 mg/cm2 to about 25 mg/cm2”, followed by a series of narrower ranges e.g., “about 0.75 mg/cm2 to about 20 mg/cm2 …”. The claims are considered indefinite because there is a question or doubt as to whether the feature introduced by such narrower language is (a) merely exemplary of the remainder of the claim, and therefore not required, or (b) a required feature of the claims.
Regarding claim 11, a broad range or limitation together with a narrow range or limitation that falls within the broad range or limitation (in the same claim) may be considered indefinite if the resulting claim does not clearly set forth the metes and bounds of the patent protection desired. See MPEP § 2173.05(c). In the present instance, claim 11 recites a broad range i.e., “about -0.2 or less” or “about -1 or less”, as well as a series of narrower ranges. The claim is considered indefinite because there is a question or doubt as to whether the feature introduced by such narrower language is (a) merely exemplary of the remainder of the claim, and therefore not required, or (b) a required feature of the claims.
Furthermore, the values are recited without units e.g., V or mV, and it is therefore unclear which specific potential values are being recited.
Furthermore, it is unclear, based on the specification, what is meant by “or less” in each of the recited ranges. I.e., it is unclear whether the limitation “or less” is meant to indicate values more negative than the recited values, or less negative than the recited values. For example, it is unclear whether the limitation “about -0.2 or less” encompasses the values -0.1 V or -0.3 V.
Claim 11 is therefore indefinite.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-3, 5-7, and 9-13 are rejected under 35 U.S.C. 103 as being unpatentable over Yu et al. (“Promoting selective electroreduction of nitrates to ammonia over electron-deficient Co modulated by rectifying Schottky contacts” Sci China Chem, 2020, 63: 1469–1476 and SI) in view of Botte (US Pat. Pub. 2009/0095636 A1) and as evidenced by, in the case of claims 10-11, Jerkiewicz (“Standard and Reversible Hydrogen Electrodes: Theory, Design, Operation, and Applications” ACS Catal. 2020, 10, 8409−8417).
Regarding claim 1, Yu 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);
wherein the catalyst comprises cobalt (“Co/CoO nanosheet arrays (Co/Co NSAs)” abstract and § 3.1 and “Co NSAs” § 2.1.4) on a support (“on Ni foams” § 3.1 and Fig. 1a, see also § 2.1);
wherein the support comprises a metal (“Ni foams” § 3.1.).
Yu does not teach the metal support is in the form of a foil, mesh, cloth, gauze, sponge, or combinations thereof.
However, Botte teaches that nickel foil or gauze is a suitable substrate for the electrodeposition of electrocatalysts (para. 16) for the production of ammonia (abstract).
As Yu and Botte each teach methods for the electrochemical production of ammonia using an electrocatalysts formed by electrodeposition on a substrate, Yu and Botte 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 Yu, such that the substrate comprises a metal foil or gauze, as taught by Botte. A person having ordinary skill in the art would have been motivated to make this modification because Botte teaches a metal foil or gauze is a suitable substrate for the electrodeposition of an electrocatalyst for the production of ammonia. Simple substitution of one known element for another to achieve predictable results (i.e., using a nickel foil or gauze in place of a nickel foam as an electrode substrate) 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 (i.e., a nickel foil or gauze as an electrode substrate) establishes a prima facie case of obviousness (MPEP § 2144.07).
Regarding claim 2, modified Yu does not teach the cobalt loading is within any of the recited ranges.
Yu instead teaches the cobalt loading is about 0.3 mg/cm2 (“Ni foams (3 cm×1 cm)” § 2.1.2 and “The loading amount of Co/CoO NSAs on Ni foams was ~0.9 mg” § 3.1 para. 2).
However, Botte further teaches a catalyst loading of about 2.5 mg/cm2, a value within each of the claimed ranges, is suitable as the catalyst loading for the electrochemical production of ammonia (“4 cm2-metallic substrates … electroplated with 10±0.1 mg of Ni” para. 16).
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 Yu, such that the catalyst loading is about 2.5 mg/cm2, a value within each of the claimed ranges, 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 catalyst loading for the electrochemical production of 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 claim 3, modified Yu renders the limitations of claim 1 obvious, as described above.
Yu further teaches the support comprises nickel (“Ni foams” § 3.1).
Furthermore, Botte renders a titanium substrate obvious (see para. 16).
Regarding claim 5, modified Yu renders the limitations of claim 1 obvious, as described above.
Yu further teaches the cobalt is deposited on the support using electrodeposition (“a simple electrodeposition method” § 3.1 para 1).
Regarding claim 6, modified Yu does not teach the cobalt is deposited on the support using a method comprising electroplating.
However, Botte further teaches that electroplating is a suitable method for forming a metal catalyst on a nickel substrate (“metallic substrates (Ni foil, Ni gauze, Ti foil and Ti gauze) that have been electroplated with 10±0.1 mg of Ni” para. 16).
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 Yu, such that the cobalt deposition method is electroplating, as taught by Botte. A person having ordinary skill in the art would have been motivated to make this modification because Botte teaches electroplating is a suitable means for depositing a metal electrocatalyst on a nickel substrate. Simple substitution of one known element for another to achieve predictable results establishes a prima facie case of obviousness (MPEP § 2143(I)(B)).
Regarding claim 7, modified Yu does not teach the nitrate is present in a composition comprising KOH, KNO3, or a combination thereof.
Yu instead teaches the nitrate is present in a composition comprising NaNO3 (§ 2.3).
However, the composition of Yu 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 Yu by substituting KNO3 in place of NaNO3. Close structural similarity between claimed chemical compositions establishes a prima facie case of obviousness (MPEP § 2144.09).
Regarding claim 9, modified Yu renders the limitations of claim 1 obvious, as described above.
Yu further teaches the ammonia producing current density is about 60 mA/cm2, a value within each of the claimed ranges (Fig. 3a shows the current density is -80 mA/cm2 at -1.6 V vs. SCE, and Fig. 3b indicates the FE is about 75% at this potential, note that Yu uses an opposite current signing convention from the instant application).
Regarding claims 10 and 11, modified Yu renders the limitations of claim 1 obvious, as described above.
Yu further teaches the process is conducted at a potential of -0.95 to -0.45 V vs. RHE (-1.6 to -1.1 V vs. SCE Fig. 3 and see calculations, below), a range within at least the claimed ranges “about -0.2 V to about -2 V” (claim 10) and “about -0.2 or less” or “about -1 or less” (claim 11, depending on the interpretation of “or less” and treating the units as V).
Calculations: Potentials in Yu were converted from SCE to SHE by adding 241 mV. The electrochemical measurements in Yu were conducted at about pH 7 (§ 2.3 indicates no pH adjusting species were present in the solution). Potentials vs. SHE were therefore converted to potentials vs. RHE by adding 7*0.059 V i.e., 413 mV (see Jerkiewicz Fig. 3).
Regarding claim 12, modified Yu renders the limitations of claim 1 obvious, as described above.
Yu further teaches the coulombic efficiency for nitrate-to-ammonia conversion is 93.8 %, a value within a plurality of the claimed ranges (“the FE of ammonia achieved the highest value of 93.8%” § 3.3, see also Fig. 3b and SI § 2).
Regarding claim 13, modified Yu renders the limitations of claim 1 obvious, as described above.
Yu further teaches the coulombic efficiency for nitrate-to-nitrite conversion is about 0%, a value within the claimed ranges (Fig. S9 shows no nitrite is produced at a potential of -1.6 V vs. SCE).
Claims 7-8 are rejected under 35 U.S.C. 103 as being unpatentable over Yu in view of Botte, as applied to claim 1 above, and further in view of McEnaney (US Pat. Pub. 2021/0301408 A1).
Regarding claim 7, modified Yu renders the limitations of claim 1 obvious, as described above.
Modified Yu does not teach the nitrate is present in a composition comprising KOH, KNO3, or a combination thereof.
Yu instead teaches the nitrate is present in a composition comprising NaNO3 (§ 2.3).
However, McEnaney teaches a method for the electrochemical reduction of nitrate to ammonia (title and abstract), wherein the nitrate is present in a composition comprising a combination of KOH and KNO3 (“Nitrate concentrations were adjusted with KNO3, and pH was controlled by using HNO3 and KOH at the desired proton or hydroxide concentration.” and “four pH values (-0.77, 2.95, 10.05, and 13.00)” para. 37).
As McEnaney teaches a method for the electrochemical reduction of nitrate to ammonia, McEnaney 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 Yu, such that the nitrate is present in a composition comprising KOH and KNO3, as taught by McEnaney. A person having ordinary skill in the art would have been motivated to make this modification because McEnaney teaches a composition comprising KOH and KNO3 is suitable as the nitrate medium 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 claim 8, modified Yu, via McEnaney, further teaches the nitrate is present in a composition comprising KOH and KNO3 (para. 37).
Claims 1, 3-7, and 9-13 are rejected under 35 U.S.C. 103 as being unpatentable over Yu et al. (“Promoting selective electroreduction of nitrates to ammonia over electron-deficient Co modulated by rectifying Schottky contacts” Sci China Chem, 2020, 63: 1469–1476 and SI) in view of Shih et al. (“Manipulating the crystalline morphology and facet orientation of copper and copper-palladium nanocatalysts supported on stainless steel mesh with the aid of cationic surfactant to improve the electrochemical reduction of nitrate and N2 selectivity” Applied Catalysis B: Environmental 273 (2020) 119053) and as evidenced by, in the case of claims 10-11, Jerkiewicz (“Standard and Reversible Hydrogen Electrodes: Theory, Design, Operation, and Applications” ACS Catal. 2020, 10, 8409−8417).
Regarding claim 1, Yu 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);
wherein the catalyst comprises cobalt (“Co/CoO nanosheet arrays (Co/Co NSAs)” abstract and § 3.1 and “Co NSAs” § 2.1.4) on a support (“on Ni foams” § 3.1 and Fig. 1a, see also § 2.1);
wherein the support comprises a metal (“Ni foams” § 3.1.).
Yu does not teach the metal support is in the form of a foil, mesh, cloth, gauze, sponge, or combinations thereof.
However, Shih teaches that a metal mesh is a suitable catalyst substrate for the electrochemical reduction of nitrate (abstract and § 2.1.).
As Yu and Shih each teach methods for the electrochemical reduction of nitrate, Yu and Shih 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 Yu, such that the substrate comprises a metal mesh, as taught by Shih. A person having ordinary skill in the art would have been motivated to make this modification because Shih teaches a metal mesh is a suitable substrate for nitrate reduction electrocatalysts. Simple substitution of one known element for another to achieve predictable results (i.e., using a mesh in place of a foam as an electrode substrate) 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 (i.e., a stainless steel mesh as an electrocatalyst substrate for nitrate reduction) establishes a prima facie case of obviousness (MPEP § 2144.07).
Regarding claim 3, Yu further teaches the support comprises nickel (“Ni foams” § 3.1).
Furthermore, Shih renders a support comprising stainless steel obvious (“stainless steel (SS) mesh” § 2.1.).
Regarding claim 4, modified Yu renders the limitations of claim 1 obvious, as described above.
Modified Yu further teaches, via Shih, the support has a mesh count of 80 per inch (“80 per inch” § 2.1.), a value within each of the claimed ranges.
Regarding claim 5, modified Yu renders the limitations of claim 1 obvious, as described above.
Yu further teaches the cobalt is deposited on the support using electrodeposition (“a simple electrodeposition method” § 3.1 para 1).
Regarding claim 6, modified Yu does not teach the cobalt is deposited on the support using a method comprising electroplating.
However, Shih further teaches that electroplating is a suitable method for forming a metal catalyst on a metal substrate (“Electrochemical plating of Cu/SS and Pd-Cu/SS electrodes” § 2.1. title).
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 Yu, such that the cobalt deposition method is electroplating, as taught by Shih. A person having ordinary skill in the art would have been motivated to make this modification because Shih teaches electroplating is a suitable means for depositing a metal electrocatalyst on a metal substrate. Simple substitution of one known element for another to achieve predictable results establishes a prima facie case of obviousness (MPEP § 2143(I)(B)).
Regarding claim 7, modified Yu does not teach the nitrate is present in a composition comprising KOH, KNO3, or a combination thereof.
Yu instead teaches the nitrate is present in a composition comprising NaNO3 (§ 2.3).
However, Shih further teaches that KNO3 is suitable as the nitrate source for electrochemical nitrate reduction (“solution containing 0 to 10-2 M KNO3” Fig. 4 caption, see also § 2.3. para. 1).
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 Yu, such that the nitrate is present as KNO3, as taught by Shih. A person having ordinary skill in the art would have been motivated to make this modification because Shih teaches KNO3 is suitable as the nitrate source in electrochemical nitrate reduction. 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).
Furthermore, the composition of Yu 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 Yu by substituting KNO3 in place of NaNO3. Close structural similarity between claimed chemical compositions establishes a prima facie case of obviousness (MPEP § 2144.09).
Regarding claim 9, modified Yu renders the limitations of claim 1 obvious, as described above.
Yu further teaches the ammonia producing current density is about 60 mA/cm2, a value within each of the claimed ranges (Fig. 3a shows the current density is -80 mA/cm2 at -1.6 V vs. SCE, and Fig. 3b indicates the FE of ammonia is about 75% at this potential, note that Yu uses an opposite current signing convention from the instant application).
Regarding claims 10 and 11, modified Yu renders the limitations of claim 1 obvious, as described above.
Yu further teaches the process is conducted at a potential of -0.95 to -0.45 V vs. NHE (-1.6 to -1.1 V vs. SCE Fig. 3 and see calculations, below), a range within at least the claimed ranges “about -0.2 V to about -2 V” (claim 10) and “about -0.2 or less” or “about -1 or less” (claim 11, depending on the meaning of “or less” and interpreting the units as V).
Calculations: Potentials in Yu were converted from SCE to SHE by adding 241 mV. The electrochemical measurements in Yu were conducted at about pH 7 (§ 2.3 indicates no pH adjusting species were present in the solution). Potentials vs. SHE were therefore converted to potentials vs. RHE by adding 7*0.059 V i.e., 413 mV (see Jerkiewicz Fig. 3).
Regarding claim 12, modified Yu renders the limitations of claim 1 obvious, as described above.
Yu further teaches the coulombic efficiency for nitrate-to-ammonia conversion is 93.8 %, a value within a plurality of the claimed ranges (“the FE of ammonia achieved the highest value of 93.8%” § 3.3, see also Fig. 3b and SI § 2).
Regarding claim 13, modified Yu renders the limitations of claim 1 obvious, as described above.
Yu further teaches the coulombic efficiency for nitrate-to-nitrite conversion is about 0%, a value within the claimed ranges (Fig. S9 shows no nitrite is produced at a potential of -1.6 V vs. SCE).
Claims 14-17 and 19-20 are rejected under 35 U.S.C. 103 as being unpatentable over Fajardo et al. (“Earth-abundant elements a sustainable solution for electrocatalytic reduction of nitrate” Applied Catalysis B: Environmental 281 (2021) 119465) in view of McEnaney (US Pat. Pub. 2021/0301408 A1).
Regarding claim 14, Fajardo teaches a process for converting nitrate to ammonia (abstract and see Fig. 3 and Table 1), comprising:
electrochemically converting nitrate in the presence of a catalyst to form a product comprising ammonia (§§ 3.1-3.2 and see Fig. 3 and Table 1);
wherein the catalyst comprises cobalt (“cobalt (99.9 %, Fine Metals)” § 2.1. para. 2 and “Co had the highest nitrate reduction kinetics (∼1.8-fold higher than Pt) and produced the lowest nitrite (< 0.08 mg NO2−-N L-1) throughout the experiment” p. 4 para bridging cols. 1 and 2, see also Fig. 3 and Table 1).
Fajardo does not teach the cobalt is in a form selected from the group consisting of a foil, mesh, cloth, gauze, sponge, or combinations thereof.
However, McEnaney teaches a method for the electrochemical reduction of nitrate to ammonia (title and abstract), wherein the catalyst is in the form of a foil (“Ti foil cathodes” para. 41) and may comprise cobalt metal (“Several cathode materials including Ti, steel, Zn, Al, Ga, Pb, Co, Ta, Fe, Ni, Mo, Re, titanium alloys, and metal compounds are presented herein.” para. 32, see also paras. 27 and 31).
As Fajardo and McEnaney each teach methods for the electrocatalytic reduction of nitrate to ammonia, Fajardo and McEnaney 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 Fajardo, such that the cobalt is in the form of a foil, as taught by McEnaney. A person having ordinary skill in the art would have been motivated to make this modification because McEnaney teaches a foil is a suitable form for the cathode in an electrocatalytic nitrate to ammonia reduction method. 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 (i.e., a metal foil as a cathode for nitrate reduction) establishes a prima facie case of obviousness (MPEP § 2144.07).
Regarding claim 15, Fajardo further teaches the catalyst comprises 99.9% cobalt, a value within each of the claimed ranges (“cobalt (99.9 %, Fine Metals)” § 2.1. para. 2).
Regarding claim 16, modified Fajardo renders the limitations of claim 14 obvious, as described above.
Fajardo further teaches the catalyst does not comprise a support (“commercial sheet parallel electrodes” § 2.1. para. 2).
Regarding claim 17, modified Fajardo renders the limitations of claim 14 obvious, as described above.
Modified Fajardo does not teach the nitrate is present in a composition comprising KOH, KNO3, or a combination thereof.
Fajardo instead teaches the nitrate is present as sodium nitrate (“Reagent grade sodium nitrate” §. 2.1. para. 1).
However, McEnaney further teaches the nitrate is present in a composition comprising a combination of KOH and KNO3 (“Nitrate concentrations were adjusted with KNO3, and pH was controlled by using HNO3 and KOH at the desired proton or hydroxide concentration.” and “four pH values (-0.77, 2.95, 10.05, and 13.00)” para. 37).
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 Fajardo, such that the nitrate is present in a composition comprising KOH and KNO3, as taught by McEnaney. A person having ordinary skill in the art would have been motivated to make this modification because McEnaney teaches a composition comprising KOH and KNO3 is suitable as the nitrate medium 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)).
Furthermore, the composition of Fajardo 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 Fajardo by substituting KNO3 in place of NaNO3. Close structural similarity between claimed chemical compositions establishes a prima facie case of obviousness (MPEP § 2144.09).
Regarding claim 19, modified Fajardo renders the limitations of claim 14 obvious, as described above.
Modified Fajardo does not teach the process is conducted at a potential vs. RHE within the claimed ranges.
Fajardo is silent as to the applied potential.
However, McEnaney further teaches the process is conducted at a potential of -0.5 to -1.5 V vs. RHE (Fig. 7a and “an applied potential of -1 V vs RHE” para. 22), a range within, overlapping, or encompassing the claimed ranges.
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 to the method of Fajardo, such that the applied potential is between -0.5 and -1.5 V vs. RHE, a range within, overlapping, or encompassing the claimed ranges, as taught by McEnaney. A person having ordinary skill in the art would have been motivated to make this modification because Fajardo is silent as to the applied potential and McEnaney teaches potentials in this range are suitable for the electrochemical reduction of nitrate to ammonia. Furthermore, simple substitution of one known element for another to achieve predictable results establishes a prima facie case of obviousness (MPEP § 2143(I)(B)).
Regarding claim 20, modified Fajardo renders the limitations of claim 14 obvious, as described above.
Fajardo does not explicitly teach the coulombic efficiency for nitrate-to-ammonia conversion within one of the recited ranges. Fajardo is silent as to the coulombic efficiency.
However, McEnaney further teaches the coulombic efficiency for nitrate-to-ammonia conversion is 78%, a value within the two of the claimed ranges (“At peak selectivity performance conditions, it is shown that there is a 78% Faradaic efficiency to ammonia” para. 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 Fajardo, such that the coulombic efficiency for nitrate-to-ammonia conversion is 78%, a value within the two of the claimed ranges, as taught by McEnaney. A person having ordinary skill in the art would have been motivated to make this modification because McEnaney teaches this is a suitable coulombic efficiency for the conversion 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)).
Claim 18 is rejected under 35 U.S.C. 103 as being unpatentable over Fajardo in view of McEnaney, as applied to claim 14 above, and further in view of Yu et al. (“Promoting selective electroreduction of nitrates to ammonia over electron-deficient Co modulated by rectifying Schottky contacts” Sci China Chem, 2020, 63: 1469–1476 and SI).
Regarding claim 18, modified Fajardo renders the limitations of claim 14 obvious, as described above.
Modified Fajardo does not teach the ammonia producing current density is within one of the recited ranges.
Fajardo is silent as to the ammonia producing current density.
However, Yu teaches a method for the electrochemical reduction of nitrate to ammonia (title and abstract) using a cobalt catalyst (abstract), wherein the ammonia producing current density is about 60 mA/cm2, a value within each of the claimed ranges (Fig. 3a shows the current density is -80 mA/cm2 at -1.6 V vs. SCE, and Fig. 3b indicates the FE of ammonia is about 75% at this potential).
As Yu teaches a method for electrochemically reducing nitrate to ammonia, Yu is analogous art to the instant specification.
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 Fajardo, such that the ammonia producing current density is about 60 mA/cm2, a value within each of the claimed ranges, as taught by Yu. A person having ordinary skill in the art would have been motivated to make this modification because Yu teaches this is a suitable current density for the electrochemical reduction of nitrate to ammonia by a cobalt catalyst. Simple substitution of one known element for another to achieve predictable results establishes a prima facie case of obviousness (MPEP § 2143(I)(B)).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Ghosh et al. (“Electrocatalytic reduction of nitrate by in situ generated cobalt nanoparticles†” Chem. Commun., 2022, 58, 4783) teaches a cobalt nanoparticle catalyst supported on glassy carbon for the electrochemical reduction of nitrate to ammonia. Li et al. (“High-efficiency nitrate electroreduction to ammonia on electrodeposited cobalt–phosphorus alloy film†” Chem. Commun., 2021, 57, 9720) teaches a method for the electrochemical reduction of nitrate to ammonia using a cobalt catalyst.
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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