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 .
Summary
The Applicant’s arguments and claim amendments received on September 30, 2025 are entered into the file. Currently, claim 2 is amended; claims 9-20 are cancelled; and claims 21-32 are new; resulting in claims 1-8 and 21-32 pending for examination.
Claim Rejections - 35 USC § 102
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 the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claims 1-2, 4-5, and 8 are rejected under 35 U.S.C. 102(a)(2) as being anticipated by García de Arquer, et al. (US 2022/0396889 A1).
Regarding claims 1 and 8, García teaches a catalyst system for gas-phase electrolysis of a reactant gas to form a product in an aqueous medium, wherein the catalyst system (cathode catalyst layer) includes a catalytical material (substrate) and one or more ion-conducting polymer layers provided on the catalytic material (¶ [0004], Ln. 1-7). The ion-conducting polymer comprises an ionomer or combination of different ionomers, and the ionomer includes a backbone that comprises hydrophobic groups and side chains that comprise hydrophilic groups (¶ [0030], Ln. 1-5). García further teaches that the ionomers are assembled into distinct hydrophobic and hydrophilic layered domains (alternating layers of hydrophobic backbone and hydrophilic sidechains) (¶ [0224], Ln. 2-6). Additionally, García teaches that the ion-conducting polymer is spray-coated directly onto an outer surface of the catalytic material to form the one or more ion-conducting polymer layers (¶ [0031], Ln. 1-3). Specifically, the polymer is coated onto a hydrophilic metal catalyst (¶ [0227], Ln. 1-6). Based on this teaching, the hydrophilic side chain layer would be exposed to the hydrophilic metal catalyst and the hydrophobic backbone layer would be the outer layer. As evidence of a hydrophobic outer layer, García teaches that the static contact angle of the catalyst surface is 121-122° (¶ [0234], Ln. 1-8), indicating a highly hydrophobic surface (free from hydrophilic groups).
Regarding claim 2, García teaches all of the limitations of claim 1 above and further teaches that the ionomer comprises a perfluorinated sulfonic acid ionomer, providing the example of sulfonated tetrafluoroethylene based fluoropolymer-copolymer such as Nafion™ (hydrophobic backbone includes PTFE and hydrophilic sidechains include sulfonate side chains) (¶ [0030], Ln. 3-9).
Regarding claim 4, García teaches all of the limitations of claim 1 above and further teaches that the ion-conducting polymer is spray-coated directly onto an outer surface of the catalytic material (substrate) (¶ [0031], Ln. 1-3), adhering the ionomer to the catalytic material (substrate) over the entire surface where the ionomer and catalytic material (substrate) share a common boundary (substrate-ionomer interface).
Regarding claim 5, García teaches that the catalyst design facilitates efficient CO2 and CO gas-phase electrolysis with an ionomer layer that, with asymmetric hydrophobic and hydrophilic functionalities, assembles into a morphology with differentiated gas and ion long-range transport routes, conformally, over the metal surface (¶ [0221], Ln. 1-10). García further teaches that in this context, conformally means a similar thickness all over the catalyst (¶ [0221], Ln. 10-11). Based on this teaching, the hydrophobic outer layer of the ionomer would be continuous all over the catalyst.
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 3 and 6 are rejected under 35 U.S.C. 103 as being unpatentable over García de Arquer, et al. (US 2022/0396889 A1) as applied to claim 1 above, and further in view of Sezer, et al. Oxidative acid treatment of carbon nanotubes. Surfaces and Interfaces, Vol. 14 (2019), pp. 1-8, cited on IDS.
Regarding claim 3, García teaches all of the limitations of claim 1 above and further teaches that the catalytic material (substrate) comprises a catalytic metal and/or carbon (¶ [0004], Ln. 5-6). García does not expressly teach that the catalytic material (substrate) is a carbon substrate having a partially oxidized non-graphitic surface.
Sezer teaches an oxidative acid treatment of carbon nanotubes. Sezer teaches that by functionalizing carbon nanotubes, chemical groups such as carboxyl, carbonyl, and hydroxyl (partially oxidized non-graphitic), are formed on the carbon nanotube surfaces, which improve their wettability and improve interfacial adhesion of the carbon nanotubes with polymers (Col. 1, Ln. 7-15).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the carbon substrate of García to include functionalized carbon nanotubes, forming chemical groups such as carboxyl, carbonyl, and hydroxyl, as taught by Sezer. One of ordinary skill in the art would be motivated to make this modification in order to improve the wettability of the substrate and improve interfacial adhesion with the ion-conducting polymer layers.
Regarding claim 6, García teaches all of the limitations of claim 1 above. García in view of Sezer teaches a substrate with functionalized carbon nanotubes, including a partially oxidized substrate with improved wettability and polymer adhesion. García in view of Sezer does not expressly teach a substrate with a water contact angle of below about 85°.
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the substrate of García in view of Sezer to have a water contact angle of below about 85°. By including functionalized carbon nanotubes in the substrate, the wettability of the substrate is improved and the water contact angle would be decreased. Any water contact angle less than 90° is considered hydrophilic. One of ordinary skill in the art would recognize that by modifying the substrate to improve wettability and improve adhesion to the hydrophilic sidechains of the ion-conducting polymer, the water contact angle would preferably be below 90°, such as below about 85°.
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over García de Arquer, et al. (US 2022/0396889 A1) as applied to claim 1 above, and further in view of Linder, et al. (US 8,455,557 B2), cited on IDS.
Regarding claim 7, García teaches all of the limitations of claim 1 above. García does not expressly teach that the hydrophobic surface is cross-linked.
Linder teaches forming membranes from polymers or polymer blends by crosslinking (Col. 7, Ln. 31-35), including membranes formed from partially fluorinated polymers (Col. 26, Ln. 48-55), such as Nafion™. Linder teaches that crosslinking may be used to modify existing membranes, such as fuel cell membranes, to improve their performance, for example, by improving rejection (Col. 9, Ln. 20-24).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the perfluorinated sulfonic acid ionomer of García to be a crosslinked membrane as taught by Linder. One of ordinary skill in the art would be motivated to modify the ionomer in order to improve the performance of the membrane, for example, by improving rejection.
Claims 21-29, and 31-32 are rejected under 35 U.S.C. 103 as being unpatentable over García de Arquer, et al. (US 2022/0396889 A1) in view of Kim, et al. (US 10,622,657 B1).
Regarding claims 21-23, 25, and 27-29, García teaches a catalyst system for gas-phase electrolysis of a reactant gas to form a product in an aqueous medium, wherein the catalyst system (cathode catalyst layer) includes a catalytical material (substrate) and one or more ion-conducting polymer layers provided on the catalytic material (¶ [0004], Ln. 1-7). The ion-conducting polymer comprises an ionomer or combination of different ionomers, and the ionomer includes a backbone that comprises hydrophobic groups and side chains that comprise hydrophilic groups (¶ [0030], Ln. 1-5). García further teaches the controlled assembly of perfluorinated sulfonic acid ionomers into distinct hydrophobic and hydrophilic layered domains (alternating layers of hydrophobic backbone and hydrophilic sidechains) (¶ [0224], Ln. 1-6). Additionally, García teaches that the ion-conducting polymer is spray-coated directly onto an outer surface of the catalytic material to form the one or more ion-conducting polymer layers (¶ [0031], Ln. 1-3). Specifically, the polymer is coated onto a hydrophilic metal catalyst (¶ [0227], Ln. 1-6). Based on this teaching, the hydrophilic side chain layer would adhere to the hydrophilic metal catalyst, leaving the hydrophobic backbone layer as the outer layer. As evidence of a hydrophobic outer layer, García teaches that the static contact angle of the catalyst after ionomer modification is 121-122° (¶ [0234], Ln. 1-8), indicating a highly hydrophobic surface (free from hydrophilic groups). García does not expressly teach a cross-linked hydrophobic surface at the outermost layer, such that the outermost layer repels water and maintains hydrophobicity during operation of a device including the cathode catalyst layer.
Kim teaches the benefits of using crosslinked polymeric materials for use as membrane materials for fuel cells (Col. 35, Ln. 7-8). Kim teaches that using cross-linkable polymers enhances the mechanical properties and dimensional stability (Col. 35, Ln. 11-13). Specifically, Kim teaches that cross-linking has been shown to reduce water uptake in polymer electrolytes (Col. 35, Ln. 23-27).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the polymer of García to include a cross-linked hydrophobic surface based on the teachings of Kim, as Kim teaches the benefits of cross-linking polymeric materials used in fuel cell membranes. One of ordinary skill in the art would be motivated to cross-link the hydrophobic surface in order to enhance the dimensional stability of the polymer, such that water uptake is reduced. The modified, cross-linked hydrophobic layer of the polymer would prevent reorientation of the hydrophobic layer during operating conditions, affixing the outer hydrophobic backbone in place and creating a continual, permanent hydrophobic layer capable of repelling water.
Regarding claim 24, García in view of Kim teaches all of the limitations of claim 21 above, teaching a predominately hydrophobic surface. García further teaches that the catalyst design facilitates efficient CO2 and CO gas-phase electrolysis with an ionomer layer that, with asymmetric hydrophobic and hydrophilic functionalities, assembles into a morphology with differentiated gas and ion long-range transport routes (porous network), conformally, over the metal surface (¶ [0221], Ln. 1-10). García further teaches that in this context, conformally means a similar thickness all over the catalyst (undulating film) (¶ [0221], Ln. 10-11).
Regarding claim 26, García in view of Kim teaches all of the limitations of claim 21 above, and García further teaches that the catalytic material (substrate) comprises a catalytic metal and/or carbon (¶ [0004], Ln. 5-6). García additionally teaches that the polymer is coated onto a hydrophilic metal catalyst (¶ [0227], Ln. 1-6). García in view of Kim does not expressly teach a substrate with a water contact angle of below about 85°.
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the substrate of García in view of Kim to have a water contact angle of below about 85°. Any water contact angle less than 90° is considered hydrophilic. One of ordinary skill in the art would recognize that as the metal catalyst of García is hydrophilic, and adheres to the hydrophilic sidechains of the ion-conducting polymer, the water contact angle would preferably be below 90°, such as below about 85°.
Regarding claim 31, García in view of Kim teaches all of the limitations of claim 27 above. García in view of Kim does not expressly teach that the crosslinking is limited to the outermost portion of the lamellar film.
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the polymer of García to include a cross-linked hydrophobic surface based on the teachings of Kim, as Kim teachings the benefits of cross-linking polymeric materials used in fuel cell membranes. One of ordinary skill in the art would be motivated to cross-link the hydrophobic surface in order to enhance the dimensional stability of the polymer, such that water uptake is reduced. Given that the purpose of modifying the polymer is to enhance dimensional stability and reduce water uptake, one of ordinary skill in the art would find it obvious that cross-linking the outer surface would be the most beneficial, as the outer surface is the hydrophobic surface which would be capable of taking in water if the polymer were to reorient.
Regarding claim 32, García in view of Kim teaches all of the limitations of claim 27 above and García further teaches that the ionomer comprises a perfluorinated sulfonic acid ionomer (¶ [0030], Ln. 3-9). García specifically teaches that in some implementations, the perfluorinated sulfonic acid ionomer comprises Nafion™, which includes a PTFE backbone (hydrophobic backbone includes PTFE and hydrophilic sidechains include sulfonate side chains) (¶ [0098], Ln. 1-4). Additionally, the sample preparation uses Nafion™ (¶ [0279], Ln. 1-7).
Claim 30 is rejected under 35 U.S.C. 103 as being unpatentable over García de Arquer, et al. (US 2022/0396889 A1) in view of Kim, et al. (US 10,622,657 B1) as applied to claim 27 above, and further in view of Heo, et al. (US 2023/0335756 A1).
Regarding claim 30, García in view of Kim teaches all of the limitations of claim 27 above, and García further teaches that the catalytic material (substrate) comprises a catalytic metal and/or carbon (¶ [0004], Ln. 5-6). García in view of Kim does not expressly teach that the substrate is a carbon substrate having a partially oxidized non-graphitic surface.
Heo teaches a membrane-electrode assembly including a pair of electrodes (¶ [0026], Ln. 1-5). The electrode includes a catalyst, an ionomer, and an additive (¶ [0028], Ln. 1-2). Heo teaches that the catalyst includes a support which may be selected from carbon black, carbon nanotubes, graphite, graphene, carbon fiber, carbon nanowire, and combinations thereof (¶ [0030], Ln. 1-5). Heo also teaches that the ionomer may be a perfluorinated sulfonic acid-based polymer such as Nafion™ (¶ [0032], Ln. 1-4). Heo teaches that since the surface of the carbon material is chemically stable, if a functional group such as a sulfonic acid, phosphoric acid group, or carboxyl group is directly substituted, the degree of substitution is not high. Thus, Heo teaches treating the surface of the carbon material with an aromatic hydrocarbon (partially oxidized) and then attaching the proton conductive functional group to the hydrocarbon (¶ [0036], Ln. 1-11). Heo teaches that surface-treating the carbon material allows the proton conductive functional group to be sufficiently bonded to the surface of the carbon material (¶ [0045], Ln. 1-5).
It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify the carbon substrate of García to include surface-treated carbon black (non-graphitic), based on the teachings of Heo. One of ordinary skill in the art would be motivated to surface-treat the carbon substrate of García in order to improve the bonding between the carbon substrate and the proton conductive functional groups.
Response to Arguments
Response-Claim Rejections – 35 U.S.C. 102 and 103
Applicant's arguments filed September 30, 2025 have been fully considered but they are not persuasive. The Applicant argues: that García, et al. (US 2022/0396889 A1) does not teach alternating layers of hydrophobic backbones and hydrophilic sidechains; that García does not teach an outermost layer being free from hydrophilic groups and forming a hydrophobic surface; that García does not teach a hydrophobic backbone including PTFE; that García does not teach that the substrate is adhered to the ionomer along an entire area of the substrate-ionomer interface; that Sezer, et al. (Oxidative acid treatment of carbon nanotubes. Surfaces and Interfaces) does not teach a partially oxidized non-graphitic surface; that the combination of Sezer and García would run counter to García’s teachings; that Linder, et al. (US 8,455,557 B2) does not disclose a PFSA-specific cross-linking route analogous to its aryl/PVDF chemistry, nor any selective surface-only cross-linking to yield a hydrophobic outer layer; and that the membranes of García and Linder have different functions, and one would therefore not be motivated to combine Linder’s teachings with the membrane of García.
With respect to the argument, see pages 5-6 of the remarks, that García does not teach alternating layers of hydrophobic backbones and hydrophilic sidechains, this argument is not persuasive. García teaches the controlled assembly of perfluorinated sulfonic acid ionomers into distinct hydrophobic and hydrophilic layered domains (¶ [0224], Ln. 1-6). As García teaches the ionomer includes a backbone that comprises hydrophobic groups and side chains that comprise hydrophilic groups (¶ [0030], Ln. 1-5), the reference therefore teaches layered hydrophobic backbones and hydrophilic sidechains.
With respect to the argument, see pages 6-9 of the remarks, that García does not teach an outermost layer being free from hydrophilic groups and forming a hydrophobic surface, this argument is not persuasive. García teaches that the separate hydrophilic and hydrophobic domains of the ionomer are layered (¶ [0224], Ln. 1-6), and that the catalyst substrate is hydrophilic, indicating the hydrophilic side chain layer would adhere to the hydrophilic metal catalyst. As the contact angle of the catalyst after ionomer modification is 121-122° (¶ [0234], Ln. 1-8), a highly hydrophobic outer surface is present. The highly hydrophobic outer surface indicates that the layer is free from hydrophilic groups. García additionally teaches the unmodified presence of the perfluorinated sulfonic acid ionomer after reaction (¶ [0234], Ln. 12-14). Given the teachings of the controlled assembly of perfluorinated sulfonic acid ionomers into distinct hydrophobic and hydrophilic layered domains (¶ [0224], Ln. 1-6), the hydrophilic surface may be attributed to the hydrophobic domain of the ionomer. Although García teaches a configuration in which SO3 is preferentially exposed to the electrolyte, given the teaching of layered hydrophilic and hydrophobic domains of the ionomer, and a contact angle indicating a highly hydrophobic surface of the ionomer-modified catalyst, the reference meets the claim limitation of a hydrophobic surface throughout the cathode catalyst layer.
With respect to the argument, see page 8 of the remarks, that García does not teach a hydrophobic backbone including PTFE, this argument is not persuasive. García specifically teaches that in some implementations, the perfluorinated sulfonic acid ionomer comprises Nafion™ (¶ [0098], Ln. 1-4), which includes a PTFE backbone. Additionally, the sample preparation uses Nafion™ (¶ [0279], Ln. 1-7).
With respect to the argument, see pages 8-9 of the remarks, that García does not teach that the substrate is adhered to the ionomer along an entire area of the substrate-ionomer interface, this argument is not persuasive. García teaches that the ion-conducting polymer is spray-coated directly onto an outer surface of the catalytic material (substrate) (¶ [0031], Ln. 1-3), and, due to the hydrophilicity of the catalytic material and hydrophilic side chains in the ionomer, the ionomer would adhere to the substrate over the entire area. García teaches a homogeneous, conformal ionomer coating over the entire catalyst (¶ [0027], Ln. 6-8).
With respect to the argument, see pages 10-11 of the remarks, that Sezer does not teach a partially oxidized non-graphitic surface, this argument is not persuasive. Sezer teaches that by functionalizing carbon nanotubes, chemical groups such as carboxyl, carbonyl, and hydroxyl, are formed on the carbon nanotube surfaces, which improve their wettability and improve interfacial adhesion of the carbon nanotubes with polymers (Col. 1, Ln. 7-15). In this case, the chemical groups such as carboxyl, carbonyl, and hydroxyl meet the limitation of a partially oxidized non-graphitic surface, as they are present on the surface of the carbon nanotubes.
With respect to the argument, see page 11 of the remarks, that the combination of Sezer and García would run counter to García’s teachings, this argument is not persuasive. García teaches that the ion-conducting polymer is spray-coated directly onto an outer surface of the catalytic material, (¶ [0031], Ln. 1-3) specifically, teaching that the metal catalyst is hydrophilic (¶ [0227], Ln. 1-6). Therefore, one of ordinary skill in the art would be motivated to include the functionalized carbon nanotubes of Sezer in order to improve the wettability of the substrate.
With respect to the argument, see page 12, that Linder does not disclose a PFSA-specific cross-linking route analogous to its aryl/PVDF chemistry, nor any selective surface-only cross-linking to yield a hydrophobic outer layer, this argument is not persuasive. Linder teaches the benefits of cross-linking polymers and polymer blends including membranes formed from partially fluorinated polymers (Col. 26, Ln. 48-55), such as Nafion™. Further, Linder teaches that selective membranes may be cross-linked and stabilized with respect to swelling and other significant changes in morphology (Col. 8, Ln. 59-62). In response to applicant's argument that the references fail to show certain features of the invention, it is noted that the features upon which applicant relies (i.e., Linder does not disclose a surface-only cross-linking) are not recited in the rejected claim(s). 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).
With respect to the argument, see pages 12-13 of the remarks, that the membranes of García and Linder have different functions, and one would therefore not be motivated to combine Linder’s teachings with the membrane of García, this argument is not persuasive. As stated above, the outer surface of the ionomer layer of García is hydrophobic, and therefore, one would be motivated to apply the cross-linking teachings of Linder to the outer surface of the ionomer layer in order to improve rejection.
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.
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/SARAH J JACOBSON/Examiner, Art Unit 1785
/MARK RUTHKOSKY/Supervisory Patent Examiner, Art Unit 1785
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