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 .
Claims 1-16 and 18-21 are pending for this Office Action.
Election/Restrictions
Applicant’s election without traverse of claims 1-10 and 18-21 in the reply filed on 12/30/2025 is acknowledged. Claims 11-16 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected method, there being no allowable generic or linking claim.
Claims 1-10 and 18-21 are under consideration for this Office Action.
Claim Rejections - 35 USC § 112(b)
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.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claim 21 is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 21: The limitation claiming “if measured according to the electrochemical method described in the examples” is considered to be unclear. The limitation appears to referencing something in the specification but is not in the claims (“the examples”). Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993). Therefore, any description of the method or the examples in the specification cannot be read into the claim. Additionally, “the electrochemical method“ and “the examples” lack antecedent basis (see MPEP § 2173.05(e)).
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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.
Claim(s) 1-5 is/are rejected under 35 U.S.C. 103 as being unpatentable over Zheng et al (“Sulfur-Modulated Tin Sites Enable Highly Selective Electrochemical Reduction of CO2 to Formate”, Joule, Volume 1, Issue 4, 20 December 2017, Pages 794-805) in view of Merino-Garcia et al (“Continuous electroconversion of CO2 into formate using 2 nm tin oxide nanoparticles”, Applied Catalysis B: Environmental, Volume 297, 15 November 2021, 120447).
Claim 1: Zheng discloses a catalyst comprising tin doped with sulfur (see e.g. abstract), wherein the sulfur concentration is between >0 to 50at % (see e.g. page 796, Fig 1B).
The sulfur concentration range of Zheng overlaps with the claimed range of between 0.1 to 2at %. MPEP § 2144.05 I states “In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990)”. Furthermore, Zhen teaches that the doping of sulfur causes the Gibbs free energy for formate to be negative between 0 and 25at% (see e.g. page 796, paragraph starting with “Interestingly”) and that the sulfur increased the atomic surface area (see e.g. page 797, paragraph starting with “To”). It is clear from the disclosure that the amount of sulfur effects the resulting catalytic activity. Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the catalyst of Zheng by adjusting the amount of sulfur between >0 and 50at% in the catalyst to get the desired catalyst characteristics, such as Giibb’s free energy for formate and surface area.
Zheng does not explicitly teach that the tin is in the form of tin oxide. Zheng teaches that the catalyst is used for the electrochemical reduction of carbon dioxide to formate (see e.g. abstract). Merino-Garcia teaches a catalyst for the electrochemical reduction of carbon dioxide to formate (see e.g. abstract), making it analogous art to the instant invention and Zheng (see MPEP § 2141.01(a) I). Merino-Garcia teaches the following regarding tin catalysts for these reactions (see e.g. page 2, col 2, paragraph starting with “Among”):
Among the different available electrocatalysts mainly producing formate from CO2RR, metallic tin (Sn) appears to be one of the best alternatives in terms of cost and selectivity, highlighting also its low toxicity, even though other metals such as lead (Pb) and bismuth (Bi) have also been proposed as efficient electrocatalysts for formate production [23,33–37]. Nevertheless, not only the synthesis of small size capping agent free Sn nanoparticles (NPs) is tricky, but also the structural stability of Sn NPs during CO2 electroreduction is under debate. Furthermore, the behavior of Sn NPs under industrial (high) cathode area and current density conditions represents a challenge that still needs to be solved [38]. As a consequence, either the use of oxide films on Sn electrodes or purely tin oxide (SnO2) NPs has been recently considered in literature as suitable electrocatalytic material for the production of formate from CO2RR [39–47], since SnO2 presents much higher structural stability under electrochemical conditions. In particular, a lot of attention has been focused on identifying the role of the different species present on the surface of the electrode (Sn/SnO/SnO2) during CO2RR. This surface composition-reactivity relationship has been studied in detail by Raman and IR spectroscopy [48–50] and scanning electrochemical microscopy (SECM) [51], which have demonstrated that oxide films (SnOx) on the surface of Sn electrodes play a key role by enhancing formate production and selectivity during CO2RR. Therefore, the present study aims at evaluating the application of crystalline and high specific surface area SnO2 NPs.
Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the catalyst of Zheng by replacing the tin with tin oxide as taught in Merino-Garcia because tin oxide can also reduce carbon dioxide into formate (see e.g. abstract) while being more stable at an industrial scale.
Claim 2: Zheng in view of Merino-Garcia discloses that the catalyst does not contain a precious metal (it is a zinc oxide doped with sulfur, see e.g. Zheng - abstract).
Claim 3: Zheng in view of Merino-Garcia discloses that the catalyst comprises at least 95% of the sum of the elements Sn, O, and S (it is a zinc oxide doped with sulfur, see e.g. Zheng - abstract).
Claim 4: Zheng in view of Merino-Garcia teaches a sulfur content of >0 to 50at % (see e.g. Zheng - page 796, Fig 1B). The sulfur concentration range of Zheng overlaps with the claimed range of between 1.2 to 1.6at%. MPEP § 2144.05 I states “In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990)”. Furthermore, Zhen teaches that the doping of sulfur causes the Gibbs free energy for formate to be negative between 0 and 25at% (see e.g. Zheng - page 796, paragraph starting with “Interestingly”) and that the sulfur increased the atomic surface area (see e.g. Zheng - page 797, paragraph starting with “To”). It is clear from the disclosure that the amount of sulfur effects the resulting catalytic activity. Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the catalyst of Zheng by adjusting the amount of sulfur between >0 and 50at% in the catalyst to get the desired catalyst characteristics, such as Giibb’s free energy for formate and surface area.
Claim 5: Zheng in view of Merino-Garcia discloses that sulfur atoms are dispersed in a surface of the tin (see e.g. Zheng - page 796, Fig 1A ad 1C).
Claim(s) 6-10 and 19-21 is/are rejected under 35 U.S.C. 103 as being unpatentable over Wang et al (“Sn nanoparticles deposited onto a gas diffusion layer via impregnation-electroreduction for enhanced CO2 electroreduction to formate”, Electrochimica Acta, Volume 369, 10 February 2021, 137662) in view of Zheng and Merino-Garcia.
Claim 6: Wang discloses a catalyst ink (see e.g. page 2, col 2, paragraph starting with “Preparation of IE-Sn”) comprising;
a liquid carrier (water, see e.g. page 2, col 2, paragraph starting with “Preparation of IE-Sn”);
conductive particles (carbon, see e.g. see e.g. page 2, col 2, paragraph starting with “Preparation of IE-Sn”);
optionally an ionomer (Nafion, see e.g. page 2, col 2, paragraph starting with “Preparation of IE-Sn”), and
a tin-based catalyst (see e.g. page 2, col 2, paragraph starting with “Preparation of IE-Sn” and abstract).
Wang does not explicitly teach that the catalyst is the catalyst of claim 1.
Zheng teaches a catalyst for the electrochemical reduction of carbon dioxide to formate (see e.g. abstract), making it analogous art to the instant invention and Wang (see MPEP § 2141.01(a) I). Zheng discloses that the catalyst comprises tin doped with sulfur (see e.g. abstract), wherein the sulfur concentration is between >0 to 50at % (see e.g. page 796, Fig 1B). The incorporation of sulfur into the tin lowers the Gibbs free energy of formate and increases the surface area (see e.g. Fig 1B and Fig 1D). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the catalyst of Wang by doping the tin with sulfur as taught in Zheng to lower the Gibbs free energy of formate and increases the surface area.
The sulfur concentration range of Zheng overlaps with the claimed range of between 0.1 to 2at %. MPEP § 2144.05 I states “In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990)”. Furthermore, Zhen teaches that the doping of sulfur causes the Gibbs free energy for formate to be negative between >0 and 25at% (see e.g. page 796, paragraph starting with “Interestingly”) and that the sulfur increased the atomic surface area (see e.g. page 797, paragraph starting with “To”). It is clear from the disclosure that the amount of sulfur effects the resulting catalytic activity. Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the catalyst of Zheng by adjusting the amount of sulfur between >0 and 50at% in the catalyst to get the desired catalyst characteristics, such as Giibb’s free energy for formate and surface area.
Wang in view of Zheng does not explicitly teach that the tin is in the form of tin oxide. Zheng teaches that the catalyst is used for the electrochemical reduction of carbon dioxide to formate (see e.g. abstract). Merino-Garcia teaches a catalyst for the electrochemical reduction of carbon dioxide to formate (see e.g. abstract), making it analogous art to the instant invention and Wang (see MPEP § 2141.01(a) I). Merino-Garcia teaches the following regarding tin catalysts for these reactions (see e.g. page 2, col 2, paragraph starting with “Among”):
Among the different available electrocatalysts mainly producing formate from CO2RR, metallic tin (Sn) appears to be one of the best alternatives in terms of cost and selectivity, highlighting also its low toxicity, even though other metals such as lead (Pb) and bismuth (Bi) have also been proposed as efficient electrocatalysts for formate production [23,33–37]. Nevertheless, not only the synthesis of small size capping agent free Sn nanoparticles (NPs) is tricky, but also the structural stability of Sn NPs during CO2 electroreduction is under debate. Furthermore, the behavior of Sn NPs under industrial (high) cathode area and current density conditions represents a challenge that still needs to be solved [38]. As a consequence, either the use of oxide films on Sn electrodes or purely tin oxide (SnO2) NPs has been recently considered in literature as suitable electrocatalytic material for the production of formate from CO2RR [39–47], since SnO2 presents much higher structural stability under electrochemical conditions. In particular, a lot of attention has been focused on identifying the role of the different species present on the surface of the electrode (Sn/SnO/SnO2) during CO2RR. This surface composition-reactivity relationship has been studied in detail by Raman and IR spectroscopy [48–50] and scanning electrochemical microscopy (SECM) [51], which have demonstrated that oxide films (SnOx) on the surface of Sn electrodes play a key role by enhancing formate production and selectivity during CO2RR. Therefore, the present study aims at evaluating the application of crystalline and high specific surface area SnO2 NPs.
Furthermore, the catalyst of Zheng is also incorporated into an ink comprising a liquid carrier (isopropanol, see e.g. page 2, col 2, paragraph starting with “The preparation”);
optionally an ionomer (Nafion, see e.g. page 2, col 2, paragraph starting with “The preparation”); and
the tin oxide catalyst (see page 2, col 2, paragraph starting with “The preparation”) and abstract).
Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the catalyst of Wang in view of Zheng by replacing the tin with tin oxide as taught in Merino-Garcia because tin oxide can also reduce carbon dioxide into formate (see e.g. abstract) while being more stable at an industrial scale.
Claim 7: Wang in view of Zheng and Merino-Garcia discloses that the conductive particles comprise conductive carbon (see e.g. Wang - see e.g. see e.g. page 2, col 2, paragraph starting with “Preparation of IE-Sn”).
Claim 8: Wang in view of Zheng and Merino-Garcia discloses an alkaline ionomer binder (Nafion, see e.g. Wang - page 2, col 2, paragraph starting with “Preparation of IE-Sn”).
Claim 9: Wang in view of Zheng and Merino-Garcia discloses that the liquid carrier comprises deionized water (see e.g. Wang - page 2, col 2, paragraph starting with “Preparation of IE-Sn”).
Claim 10: Wang in view of Zheng and Merino-Garcia discloses that the ink comprises ethanol (see e.g. Wang - page 2, col 2, paragraph starting with “Preparation of IE-Sn”).
Claim 19: Wang discloses a tin catalyst-containing gas diffusion electrode (see e.g. abstract) comprising a tin catalyst (see e.g. abstract) dispersed onto substrate (see e.g. page 2, col 2, paragraph starting with “Preparation of GDL”).
Wang teaches that carbon paper is a known and suitable substrate for these types of electrodes (see e.g. page 2, col 1, paragraph starting “The CL”: “The CL is typically comprised of a mixture of a binder (e.g., Nafion), carbon materials (e.g., carbon black), and Sn nanoparticles deposited onto a GDL (e.g., carbon film including of carbon black, polytetrafluoroethylene, and metal mesh; or carbon paper)”). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to select carbon paper as the substrate because KSR rationale E states that is obvious to choose “from a finite number of identified, predictable solutions, with a reasonable expectation of success” and MPEP § 2144.07 states “The selection of a known material based on its suitability for its intended use supported a prima facie obviousness determination in Sinclair & Carroll Co. v. Interchemical Corp., 325 U.S. 327, 65 USPQ 297 (1945)”.
Wang does not explicitly teach that the catalyst is the catalyst of claim 1.
Zheng teaches a catalyst for the electrochemical reduction of carbon dioxide to formate (see e.g. abstract), making it analogous art to the instant invention and Wang (see MPEP § 2141.01(a) I). Zheng discloses that the catalyst comprises tin doped with sulfur (see e.g. abstract), wherein the sulfur concentration is between 0 to 50at % (see e.g. page 796, Fig 1B). The incorporation of sulfur into the tin lowers the Gibbs free energy of formate and increases the surface area (see e.g. Fig 1B and Fig 1D). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the catalyst of Wang by doping the tin with sulfur as taught in Zheng to lower the Gibbs free energy of formate and increases the surface area.
The sulfur concentration range of Zheng overlaps with the claimed range of between 0.1 to 2at %. MPEP § 2144.05 I states “In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990)”. Furthermore, Zhen teaches that the doping of sulfur causes the Gibbs free energy for formate to be negative between >0 and 25at% (see e.g. page 796, paragraph starting with “Interestingly”) and that the sulfur increased the atomic surface area (see e.g. page 797, paragraph starting with “To”). It is clear from the disclosure that the amount of sulfur effects the resulting catalytic activity. Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the catalyst of Zheng by adjusting the amount of sulfur between >0 and 50at% in the catalyst to get the desired catalyst characteristics, such as Giibb’s free energy for formate and surface area.
Wang in view of Zheng does not explicitly teach that the tin is in the form of tin oxide. Zheng teaches that the catalyst is used for the electrochemical reduction of carbon dioxide to formate (see e.g. abstract). Merino-Garcia teaches a catalyst for the electrochemical reduction of carbon dioxide to formate (see e.g. abstract), making it analogous art to the instant invention and Wang (see MPEP § 2141.01(a) I). Merino-Garcia teaches the following regarding tin catalysts for these reactions (see e.g. page 2, col 2, paragraph starting with “Among”):
Among the different available electrocatalysts mainly producing formate from CO2RR, metallic tin (Sn) appears to be one of the best alternatives in terms of cost and selectivity, highlighting also its low toxicity, even though other metals such as lead (Pb) and bismuth (Bi) have also been proposed as efficient electrocatalysts for formate production [23,33–37]. Nevertheless, not only the synthesis of small size capping agent free Sn nanoparticles (NPs) is tricky, but also the structural stability of Sn NPs during CO2 electroreduction is under debate. Furthermore, the behavior of Sn NPs under industrial (high) cathode area and current density conditions represents a challenge that still needs to be solved [38]. As a consequence, either the use of oxide films on Sn electrodes or purely tin oxide (SnO2) NPs has been recently considered in literature as suitable electrocatalytic material for the production of formate from CO2RR [39–47], since SnO2 presents much higher structural stability under electrochemical conditions. In particular, a lot of attention has been focused on identifying the role of the different species present on the surface of the electrode (Sn/SnO/SnO2) during CO2RR. This surface composition-reactivity relationship has been studied in detail by Raman and IR spectroscopy [48–50] and scanning electrochemical microscopy (SECM) [51], which have demonstrated that oxide films (SnOx) on the surface of Sn electrodes play a key role by enhancing formate production and selectivity during CO2RR. Therefore, the present study aims at evaluating the application of crystalline and high specific surface area SnO2 NPs.
Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the catalyst of Wang in view of Zheng by replacing the tin with tin oxide as taught in Merino-Garcia because tin oxide can also reduce carbon dioxide into formate (see e.g. abstract) while being more stable at an industrial scale.
Claim 20: Wang in view of Zheng and Merino-Garcia discloses that the electrode comprises an ionomer (Nafion, see e.g. Wang - page 2, col 2, paragraph starting with “Preparation of IE-Sn”).
Claim 21: Wang in view of Zheng and Merino-Garcia teaches a Faradaic efficiency of at least 60% if measured according to the electrochemical method described in the examples when incorporating sulfur into the catalyst (93%, see e.g. Zheng – abstract).
Claim(s) 18 is/are rejected under 35 U.S.C. 103 as being unpatentable over Zheng.
Claim 18: The claim is a product-by-process claim. MPEP § 2113 I states ‘"[E]ven though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself. The patentability of a product does not depend on its method of production. If the product in the product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process." In re Thorpe, 777 F.2d 695, 698, 227 USPQ 964, 966 (Fed. Cir. 1985)’. According to the claim, the catalyst is reduced to metallic zin from the reduction process. Therefore, the structure of claim 18 is considered to be “A catalyst comprising tin doped with sulfur, wherein the sulfur concentration is between 0.1 to 2at %”, which is just the catalyst of claim 1 with the tin oxide reduced to tin.
Zheng discloses a catalyst comprising tin doped with sulfur (see e.g. abstract), wherein the sulfur concentration is between >0 to 50at % (see e.g. page 796, Fig 1B).
The sulfur concentration range of Zheng overlaps with the claimed range of between 0.1 to 2at %. MPEP § 2144.05 I states “In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990)”. Furthermore, Zhen teaches that the doping of sulfur causes the Gibbs free energy for formate to be negative between >0 and 25at% (see e.g. page 796, paragraph starting with “Interestingly”) and that the sulfur increased the atomic surface area (see e.g. page 797, paragraph starting with “To”). It is clear from the disclosure that the amount of sulfur effects the resulting catalytic activity. Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the catalyst of Zheng by adjusting the amount of sulfur between >0 and 50at% in the catalyst to get the desired catalyst characteristics, such as Giibb’s free energy for formate and surface area.
Furthermore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention that the catalyst of Zheng renders the product of claim 18 obvious because the two products are substantially similar in structure.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ALEXANDER W KEELING whose telephone number is (571)272-9961. The examiner can normally be reached 7:30 AM - 4:00 PM. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Luan 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 W KEELING/Primary Examiner, Art Unit 1795