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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 05/06/2026 has been entered.
Status of Rejections
All previous rejections are withdrawn in view of applicant’s amendments.
New grounds of rejection are necessitated by applicant’s amendments.
Claims 1-20 are pending and under consideration for this Office Action.
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 1-3, 11-16 and 19-20 are rejected under 35 U.S.C. 103 as being unpatentable over Ballantine et al. (U.S. 2022/0023946) in view of Pushkarev et al. (“On the influence of porous transport layers parameters on the performances of polymer electrolyte membrane water electrolysis cell”, Electrochimica Acta, 2021), and further in view of Buechi et al. (U.S. 2022/0085390).
Regarding claim 1, Ballantine teaches a porous transport layer (see e.g. Fig. 1, porous anode side gas diffusion layer/transport layer 14; Paragraph 0013, lines 1-2) comprising:
a base layer comprising a titanium family element (see e.g. Paragraph 0013, lines 1-2, porous titanium sheet);
a first coating layer disposed directly on a first surface of the base layer (see e.g. Paragraph 0014, lines 2-5, coating on anode electrode side of porous titanium sheet); and
a second coating layer disposed directly on a second, opposite surface of the base layer, wherein the second coating layer comprises platinum (Pt), gold (Au) or combinations thereof (see e.g. Paragraph 0014, lines 2-6, coating comprising Pt and/or Au on flow plate side of porous titanium sheet),
wherein the porous transport layer comprises the first coating layer, the base layer, and the second coating layer stacked in order (see e.g. Paragraphs 0013-0014, porous gas diffusion layer/transport layer formed by the porous titanium sheet coated on both sides, i.e. forming a stack of the three layers).
Ballantine does not explicitly teach the first coating layer comprising iridium (Ir), but does teach that it may generally comprise be conductivity enhancing and comprise noble metals such as gold and platinum group metals (see e.g. Paragraph 0014, lines 3-6, and Paragraph 0025, lines 1-2). Ballantine further teaches iridium, which is a platinum group metal, being a suitable highly conductive noble metal (see e.g. Paragraph 0026).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the first coating layer of Ballantine to comprise iridium as taught by Ballantine as a particular suitable platinum group noble metal that can provide high conductivity to the porous transport layer. 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)”.
Ballantine does not explicitly teach particles of the titanium family element in the base layer having an average particle size in a range of 20 to 80 µm, but does generally teach the base layer having a porosity of 40-60%, being formed by a powder metallurgy process by compaction and sintering of titanium powder, i.e. particles (see e.g. Paragraph 0015), and being used on the anode side of a PEM water electrolyzer (see e.g. Paragraphs 0002-0003).
Pushkarev teaches a porous transport layer (PTL) made from sintered Ti for use in PEM water electrolysers (see e.g. Abstract), wherein a PTL with an average grain diameter of 40.2 µm has a porosity of 53.7% (see e.g. Tables 2 and 3, PTL 1) and shows good performance in use with an anode (see e.g. Page 6, under “3.3”, lines 1-8).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the base layer of Ballantine to be formed with the PTL structure of Pushkarev, having an average size of 40.2 µm and porosity of 53.7%, as a particular suitable structure for a sintered titanium porous transport layer within the desired porosity range that provides good performance with the anode of a PEM water electrolyzer. MPEP § 2143(I)(A) states that “combining prior art elements according to known methods to yield predictable results” may be obvious. The claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination would yield nothing more than predictable results.
Modified Ballantine does not explicitly teach the first coating layer having an average thickness in a range from 1 to 10 micrometers (µm), but does teach the coating being intended to provide good conductivity and corrosion resistance (see e.g. Ballantine Paragraph 0014, lines 3-7).
Buechi teaches a porous transport layer for an electrochemical cell (see e.g. Abstract) which may be provided with a corrosion protective coatings of Au, Pt and/or Ir on either side (see e.g. Fig. 2, protective layers 12 on the outer sides of PTL 2; Paragraph 0031, lines 1-2, and Paragraph 0034, lines 1-5), these protective coatings having preferential thicknesses of 0.02 to 2 µm (see e.g. Paragraph 0034, lines 5-7), overlapping the claimed range of the present invention.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the coating layers of modified Ballantine to have an average thickness of 0.02 to 2 µm as taught by Buechi as a suitable preferential thickness for noble metal-containing corrosion protective coatings for a porous transport layer of an electrochemical cell. MPEP § 2143(I)(A) states that “combining prior art elements according to known methods to yield predictable results” may be obvious. The claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination would yield nothing more than predictable results. 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.”
Regarding claim 2, modified Ballantine teaches the titanium family element comprising titanium or a combination of titanium and zirconium (see e.g. Ballantine Paragraph 0013, lines 1-2, and Paragraph 0024, lines 1-5).
Regarding claim 3, Ballantine as modified above does not explicitly teach the second coating layer further comprising ruthenium (Ru), palladium (Pd), rhodium (Rh), osmium (Os), or combinations thereof, but does teach that it may generally comprise be conductivity enhancing and comprise noble metals such as gold and platinum group metals (see e.g. Ballantine Paragraph 0014, lines 3-6, and Paragraph 0025, lines 1-2). Ballantine further teaches ruthenium, palladium, rhodium and/or osmium, which are platinum group metals, being suitable highly conductive noble metals (see e.g. Ballantine Paragraph 0026).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the second coating layer of Ballantine to further comprise ruthenium, palladium, rhodium and/or osmium as taught by Ballantine as particular suitable platinum group noble metals that can provide high conductivity to the porous transport layer. 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)”.
Regarding claim 11, Ballantine teaches a water electrolysis cell (see e.g. Fig. 1, PEM water electrolyzer 1; Paragraph 0010, lines 1-6) comprising:
a porous transport layer (see e.g. Fig. 1, porous anode side gas diffusion layer/transport layer 14; Paragraph 0013, lines 1-2) comprising:
a base layer comprising a titanium family element (see e.g. Paragraph 0013, lines 1-2, porous titanium sheet);
a first coating layer disposed directly on a first surface of the base layer (see e.g. Paragraph 0014, lines 2-5, coating on anode electrode side of porous titanium sheet); and
a second coating layer disposed directly on a second, opposite surface of the base layer, wherein the second coating layer comprises platinum (Pt), gold (Au) or combinations thereof (see e.g. Paragraph 0014, lines 2-6, coating comprising Pt and/or Au on flow plate side of porous titanium sheet),
wherein the porous transport layer comprises the first coating layer, the base layer, and the second coating layer stacked in order (see e.g. Paragraphs 0013-0014, porous gas diffusion layer/transport layer formed by the porous titanium sheet coated on both sides, i.e. forming a stack of the three layers).
Ballantine does not explicitly teach the first coating layer comprising iridium (Ir), but does teach that it may generally comprise be conductivity enhancing and comprise noble metals such as gold and platinum group metals (see e.g. Paragraph 0014, lines 3-6, and Paragraph 0025, lines 1-2). Ballantine further teaches iridium, which is a platinum group metal, being a suitable highly conductive noble metal (see e.g. Paragraph 0026).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the first coating layer of Ballantine to comprise iridium as taught by Ballantine as a particular suitable platinum group noble metal that can provide high conductivity to the porous transport layer. 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)”.
Ballantine does not explicitly teach particles of the titanium family element in the base layer having an average particle size in a range of 20 to 80 µm, but does generally teach the base layer having a porosity of 40-60% and being formed by a powder metallurgy process by compaction and sintering of titanium powder, i.e. particles (see e.g. Paragraph 0015).
Pushkarev teaches a porous transport layer (PTL) made from sintered Ti for use in PEM water electrolysers (see e.g. Abstract), wherein a PTL with an average grain diameter of 40.2 µm has a porosity of 53.7% (see e.g. Tables 2 and 3, PTL 1) and shows good performance in use with an anode (see e.g. Page 6, under “3.3”, lines 1-8).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the base layer of Ballantine to be formed with the PTL structure of Pushkarev, having an average size of 40.2 µm and porosity of 53.7%, as a particular suitable structure for a sintered titanium porous transport layer within the desired porosity range that provides good performance with the anode of a PEM water electrolyzer. MPEP § 2143(I)(A) states that “combining prior art elements according to known methods to yield predictable results” may be obvious. The claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination would yield nothing more than predictable results.
Modified Ballantine does not explicitly teach the first coating layer having an average thickness in a range from 1 to 10 micrometers (µm), but does teach the coating being intended to provide good conductivity and corrosion resistance (see e.g. Ballantine Paragraph 0014, lines 3-7).
Buechi teaches a porous transport layer for an electrochemical cell (see e.g. Abstract) which may be provided with a corrosion protective coatings of Au, Pt and/or Ir on either side (see e.g. Fig. 2, protective layers 12 on the outer sides of PTL 2; Paragraph 0031, lines 1-2, and Paragraph 0034, lines 1-5), these protective coatings having preferential thicknesses of 0.02 to 2 µm (see e.g. Paragraph 0034, lines 5-7), overlapping the claimed range of the present invention.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the coating layers of modified Ballantine to have an average thickness of 0.02 to 2 µm as taught by Buechi as a suitable preferential thickness for noble metal-containing corrosion protective coatings for a porous transport layer of an electrochemical cell. MPEP § 2143(I)(A) states that “combining prior art elements according to known methods to yield predictable results” may be obvious. The claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination would yield nothing more than predictable results. 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.”
Regarding claim 12, modified Ballantine teaches an anode bipolar plate disposed on the second coating layer of the porous transport layer (see e.g. Ballantine Fig. 1, anode flow plate 2 on respective coating side of porous titanium sheet of anode gas diffusion layer 14; Paragraph 0011, lines 1-7, and Paragraph 0014, lines 2-4); and a membrane-electrode assembly (MEA) disposed on the first coating layer (see e.g. Ballantine Fig. 1, MEA formed by anode electrode 16, PEM electrolyte 12 and cathode electrode 20 on respective coating side of porous titanium sheet of anode gas diffusion layer 14; Paragraph 0010, lines 8-15, and Paragraph 0014, lines 2-4).
Regarding claim 13, Ballantine teaches a method for preparing a porous transport layer (see e.g. Paragraph 0013, formation of porous anode side gas diffusion layer/transport layer), the method comprising:
stacking a first coating layer directly on a first surface of a base layer, wherein the base layer comprises a titanium family element (see e.g. Paragraph 0014, lines 2-5, coating on anode electrode side of porous titanium sheet); and
stacking a second coating layer directly on a second, opposite surface of the base layer, the second coating layer comprising platinum (Pt), gold (Au) or combinations thereof (see e.g. Paragraph 0014, lines 2-6, coating comprising Pt and/or Au on flow plate side of porous titanium sheet) to provide the porous transport layer having the first coating layer, the base layer, and the second coating layer stacked in order (see e.g. Paragraphs 0013-0014, porous gas diffusion layer/transport layer formed by the porous titanium sheet coated on both sides, i.e. forming a stack of the three layers).
Ballantine does not explicitly teach the first coating layer containing iridium (Ir), but does teach that it may generally comprise be conductivity enhancing and comprise noble metals such as gold and platinum group metals (see e.g. Paragraph 0014, lines 3-6, and Paragraph 0025, lines 1-2). Ballantine further teaches iridium, which is a platinum group metal, being a suitable highly conductive noble metal (see e.g. Paragraph 0026).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the first coating layer of Ballantine to comprise iridium as taught by Ballantine as a particular suitable platinum group noble metal that can provide high conductivity to the porous transport layer. 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)”.
Ballantine does not explicitly teach particles of the titanium family element in the base layer having an average particle size in a range of 20 to 80 µm, but does generally teach the base layer having a porosity of 40-60%, being formed by a powder metallurgy process by compaction and sintering of titanium powder, i.e. particles (see e.g. Paragraph 0015), and being used on the anode side of a PEM water electrolyzer (see e.g. Paragraphs 0002-0003).
Pushkarev teaches a porous transport layer (PTL) made from sintered Ti for use in PEM water electrolysers (see e.g. Abstract), wherein a PTL with an average grain diameter of 40.2 µm has a porosity of 53.7% (see e.g. Tables 2 and 3, PTL 1) and shows good performance in use with an anode (see e.g. Page 6, under “3.3”, lines 1-8).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the base layer of Ballantine to be formed with the PTL structure of Pushkarev, having an average size of 40.2 µm and porosity of 53.7%, as a particular suitable structure for a sintered titanium porous transport layer within the desired porosity range that provides good performance with the anode of a PEM water electrolyzer. MPEP § 2143(I)(A) states that “combining prior art elements according to known methods to yield predictable results” may be obvious. The claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination would yield nothing more than predictable results.
Modified Ballantine does not explicitly teach the first coating layer having an average thickness in a range from 1 to 10 micrometers (µm), but does teach the coating being intended to provide good conductivity and corrosion resistance (see e.g. Ballantine Paragraph 0014, lines 3-7).
Buechi teaches a porous transport layer for an electrochemical cell (see e.g. Abstract) which may be provided with a corrosion protective coatings of Au, Pt and/or Ir on either side (see e.g. Fig. 2, protective layers 12 on the outer sides of PTL 2; Paragraph 0031, lines 1-2, and Paragraph 0034, lines 1-5), these protective coatings having preferential thicknesses of 0.02 to 2 µm (see e.g. Paragraph 0034, lines 5-7), overlapping the claimed range of the present invention.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the coating layers of modified Ballantine to have an average thickness of 0.02 to 2 µm as taught by Buechi as a suitable preferential thickness for noble metal-containing corrosion protective coatings for a porous transport layer of an electrochemical cell. MPEP § 2143(I)(A) states that “combining prior art elements according to known methods to yield predictable results” may be obvious. The claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination would yield nothing more than predictable results. 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.”
Regarding claim 14, modified Ballantine teaches the titanium family element comprising titanium or a combination of titanium and zirconium (see e.g. Ballantine Paragraph 0013, lines 1-2, and Paragraph 0024, lines 1-5).
Regarding claim 15, Ballantine as modified above does not explicitly teach the second coating layer further comprising ruthenium (Ru), palladium (Pd), rhodium (Rh), osmium (Os), or combinations thereof, but does teach that it may generally comprise be conductivity enhancing and comprise noble metals such as gold and platinum group metals (see e.g. Ballantine Paragraph 0014, lines 3-6, and Paragraph 0025, lines 1-2). Ballantine further teaches ruthenium, palladium, rhodium and/or osmium, which are platinum group metals, being suitable highly conductive noble metals (see e.g. Ballantine Paragraph 0026).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the second coating layer of Ballantine to further comprise ruthenium, palladium, rhodium and/or osmium as taught by Ballantine as particular suitable platinum group noble metals that can provide high conductivity to the porous transport layer. 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)”.
Regarding claim 16, Ballantine as modified above does not explicitly teach each coating layer of the first coating layer and the second coating layer being independently formed using a spray coating method, a 3D printing method, an inkjet printing method, a slot die coating method, a bar coating method, a powder scattering coating method, a screen printing method, or a knife coating method.
Buechi further teaches the Au, Pt and/or Ir corrosion protective coating being made by plasma spray coating (see e.g. Buechi Paragraph 0034, lines 1-7).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of modified Ballantine to involve forming each of the first and second coating layers by plasma spray coating as taught by Buechi as a suitable means of forming a corrosion protective Au, Pt and/or Ir coating layer on a porous transport layer for an electrochemical cell. MPEP § 2143(I)(A) states that “combining prior art elements according to known methods to yield predictable results” may be obvious. The claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination would yield nothing more than predictable results.
Regarding claims 19-20, the limitations of the current density at a voltage of 2.0V and performance deterioration rate after 1000 hours both relate to the manner of intended use of the porous transport layer. MPEP § 2114 states “"[A]pparatus claims cover what a device is, not what a device does."…A claim containing a "recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from a prior art apparatus" if the prior art apparatus teaches all the structural limitations of the claim.”. Modified Ballantine teaches all the structural limitations of the claimed porous transport layer as stated above, and it would therefore be expected to be capable of exhibiting the same or very similar characteristics when in use. Furthermore, both current density and performance deterioration are properties in use that can be influenced by operational parameters outside of the structural characteristics of the porous transport layer itself, such as choice of catalyst, operating temperature/pressure and electrolyte.
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Ballantine, Pushkarev and Buechi, as applied to claim 1 above, and further in view of Sabarirajan et al. (WO 2023129549 A2).
Regarding claim 4, modified Ballantine teaches all the elements of the porous transport layer of claim 1 as stated above. Ballantine as modified by Buechi further teaches the second coating layer having an average thickness in a range from 0.02 to 2 µm (see e.g. Buechi Paragraph 0034, lines 5-7), overlapping the claimed range of the present invention (see MPEP § 2144.05 I as cited above). Modified Ballantine does not explicitly teach the base layer having an average thickness in a range from 20 to 1000 µm, but does teach it being used on the anode side of a PEM water electrolyzer (see e.g. Ballantine Paragraphs 0002-0003).
Sabarirajan teaches a porous transport layer for use on the anode side of an electrolysis cell including a catalyst coated membrane (see e.g. Paragraphs 0021-0023 and 0026), wherein the porous transport layer preferably has a thickness within a range of 100-1000 microns to provide better mass transport while not suffering from poor two phase flow effects (see e.g. Paragraph 0029).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the base layer of modified Ballantine to have a thickness of 100-1000 microns as taught by Sabarirajan to provide better mass transport while not suffering from poor two phase flow effects.
Claims 5-6 and 17 are rejected under 35 U.S.C. 103 as being unpatentable over Ballantine, Pushkarev and Buechi, as applied to claims 1 and 13 above, and further in view of Siddiqui et al. (U.S. 2007/0213209).
Regarding claim 5, modified Ballantine teaches all the elements of the porous transport layer of claim 1 as stated above. Modified Ballantine does not teach an antioxidant layer disposed on the first coating layer such that the first coating layer is positioned between the antioxidant layer and the base layer, wherein the antioxidant layer comprises a lanthanide element. Ballantine does however teach the first coating layer being adjacent to an electrode catalyst layer when the porous transport layer is provided in a proton exchange membrane electrolyzer (see e.g. Ballantine Fig. 1, Paragraph 0003, and Paragraph 0014, lines 2-4, anode electrode side coating on porous titanium sheet forming anode side gas diffusion layer of PEM electrolyzer),
Siddiqui teaches a membrane electrode assembly for a fuel cell (see e.g. Abstract) comprising a surface layer containing a catalytically active component which may be applied on a surface of a gas diffusion backing that contacts the electrode surface of the membrane (see e.g. Paragraph 0034, lines 1-5, and Paragraph 0037, lines 1-3 and 12-16), the catalytically active component serving as a hydrogen peroxide scavenger, i.e. antioxidant, to increase the hydrogen peroxide radical resistance in the membrane electrode assembly (see e.g. Paragraph 0006, lines 1-3, and Paragraph 0009) and comprising catalysts such as lanthanide elements including cerium, lanthanum and gadolinium (see e.g. Paragraph 0016).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the porous transport layer of modified Ballantine to comprise a surface layer including a hydrogen peroxide scavenger, i.e. antioxidant, comprising catalysts such as lanthanide elements including cerium, lanthanum and gadolinium provided on the first coating layer to face the electrode catalyst layer when assembled into an membrane electrolyzer as taught by Siddiqui to increase the hydrogen peroxide radical resistance of the assembled cell.
Regarding claim 6, Ballantine as modified by Siddiqui teaches the antioxidant layer having an average thickness in a range of less than 10 µm (see e.g. Siddiqui Paragraph 0034, lines 11-13), overlapping the claimed range of the present invention (see MPEP § 2144.05 I as cited above).
Regarding claim 17, modified Ballantine teaches all the elements of the method of claim 13 as stated above. Modified Ballantine does not teach stacking an antioxidant layer on the first coating layer such that the first coating layer is positioned between the antioxidant layer and the base layer, wherein the antioxidant layer comprises a lanthanide element. Ballantine does however teach the first coating layer being adjacent to an electrode catalyst layer when the porous transport layer is provided in a proton exchange membrane electrolyzer (see e.g. Ballantine Fig. 1, Paragraph 0003, and Paragraph 0014, lines 2-4, anode electrode side coating on porous titanium sheet forming anode side gas diffusion layer of PEM electrolyzer).
Siddiqui teaches a membrane electrode assembly for a fuel cell (see e.g. Abstract) comprising a surface layer containing a catalytically active component which may be applied on a surface of a gas diffusion backing that contacts the electrode surface of the membrane (see e.g. Paragraph 0034, lines 1-5, and Paragraph 0037, lines 1-3 and 12-16), the catalytically active component serving as a hydrogen peroxide scavenger, i.e. antioxidant, to increase the hydrogen peroxide radical resistance in the membrane electrode assembly (see e.g. Paragraph 0006, lines 1-3, and Paragraph 0009) and comprising catalysts such as lanthanide elements including cerium, lanthanum and gadolinium (see e.g. Paragraph 0016).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of modified Ballantine to comprise providing a surface layer including a hydrogen peroxide scavenger, i.e. antioxidant, comprising catalysts such as lanthanide elements including cerium, lanthanum and gadolinium provided on the first coating layer to face the electrode catalyst layer when assembled into a cell as taught by Siddiqui to increase the hydrogen peroxide radical resistance of the assembled cell.
Claims 7, 10 and 18 are rejected under 35 U.S.C. 103 as being unpatentable over Ballantine, Pushkarev, Buechi and Siddiqui, as applied to claims 5 and 17 above, and further in view of Fan et al. (WO 2020252606 A1, citations based on translation).
Regarding claim 7, modified Ballantine teaches all the elements of the porous transport layer of claim 5 as stated above. Modified Ballantine does not teach a bonding layer disposed on the antioxidant layer such that the antioxidant layer is positioned between the bonding layer and the first coating layer, wherein the bonding layer comprises an ionomer. Ballantine as modified by Siddiqui does however teach the first coating layer being adjacent to an electrode catalyst layer when the porous transport layer is provided in a proton exchange membrane electrolyzer (see e.g. Ballantine Fig. 1, Paragraph 0003, and Paragraph 0014, lines 2-4, anode electrode side coating on porous titanium sheet forming anode side gas diffusion layer of PEM electrolyzer), and the antioxidant layer being on the outer surface of the porous transport layer to be contacted with the electrode catalyst layer (see e.g. Siddiqui Paragraph 0037, lines 1-3 and 12-16).
Fan teaches a membrane electrode structure for a fuel cell (see e.g. Paragraph 0001) comprising a glue, i.e. bonding layer, comprising a perfluorosulfonic acid ion polymer provided on the surface of a gas diffusion layer to glue it to an electrode catalyst layer (see e.g. Paragraphs 0043 and 0050), this gluing operation providing adhesion and proton conduction (see e.g. Paragraphs 0112 and Paragraph 0113, line 13).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the porous transport layer of modified Ballantine to comprise a glue, i.e. bonding layer, comprising a perfluorosulfonic acid ion polymer provided on its outer surface as taught by Fan to provide adhesion and proton conduction between the porous transport layer and the adjacent electrode catalyst layer.
Regarding claim 10, Ballantine as modified by Siddiqui and Fan teaches the bonding layer being a continuous layer on the antioxidant layer (see e.g. Siddiqui Paragraph 0009 and Paragraph 0037, lines 1-3 and 12-16, peroxide scavenger, i.e. antioxidant, component, in surface layer on gas diffusion backing; see e.g. Fan Paragraph 0043, lines 2-3, entire surface sprayed with layer of glue, as opposed to only edges).
Regarding claim 18, modified Ballantine teaches all the elements of the method of claim 17 as stated above. Modified Ballantine does not teach stacking a bonding layer on the antioxidant layer such that the antioxidant layer is positioned between the bonding layer and the first coating layer, wherein the bonding layer comprises a hydrogen ion conductive polymer. Ballantine as modified by Siddiqui does however teach the first coating layer being adjacent to an electrode catalyst layer when the porous transport layer is provided in a proton exchange membrane electrolyzer (see e.g. Ballantine Fig. 1, Paragraph 0003, and Paragraph 0014, lines 2-4, anode electrode side coating on porous titanium sheet forming anode side gas diffusion layer of PEM electrolyzer), and the antioxidant layer being on the outer surface of the porous transport layer to be contacted with the electrode catalyst layer (see e.g. Siddiqui Paragraph 0037, lines 1-3 and 12-16).
Fan teaches a membrane electrode structure for a fuel cell (see e.g. Paragraph 0001) comprising a glue, i.e. bonding layer, comprising a perfluorosulfonic acid ion polymer provided on the surface of a gas diffusion layer to glue it to an electrode catalyst layer (see e.g. Paragraphs 0043 and 0050), this gluing operation providing adhesion and proton conduction (see e.g. Paragraphs 0112 and Paragraph 0113, line 13).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the method of modified Ballantine to comprise providing a glue, i.e. bonding layer, comprising a perfluorosulfonic acid ion polymer on the outer surface of the porous transport layer as taught by Fan to provide adhesion and proton conduction between the porous transport layer and the adjacent electrode catalyst layer.
Claims 8-9 are rejected under 35 U.S.C. 103 as being unpatentable over Ballantine, Pushkarev, Buechi, Siddiqui and Fan, as applied to claim 7 above, and further in view of Kohler et al. (U.S. 2003/0224233).
Regarding claim 8, modified Ballantine teaches all the elements of the porous transport layer of claim 7 as stated above. Modified Ballantine does not explicitly teach the bonding layer containing ionomer of an applied amount equal to or greater than 1 µg/cm2.
Kohler teaches a process for manufacturing membrane electrode assemblies (see e.g. Abstract) comprising a step of providing an adhesive component such as an ionomer on a gas diffusion layer to be laminated with a catalyst-coated membrane (see e.g. Paragraph 0029 and Paragraph 0033, lines 1-8), wherein the adhesive component is preferably provided in an amount of 10 to 1000 µg/cm2 to avoid MEA performance losses (see e.g. Paragraph 0034, lines 12-15, 0.01 to 1 mg/cm2).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the bonding layer of modified Ballantine to contain the ionomer adhesive component in an amount of 10 to 1000 µg/cm2 as taught by Kohler to avoid MEA performance losses.
Regarding claim 9, modified Ballantine teaches all the elements of the porous transport layer of claim 7 as stated above. Ballantine as modified by Siddiqui and Fan further teaches the bonding layer being on the antioxidant layer (see e.g. Siddiqui Paragraph 0009 and Paragraph 0037, lines 1-3 and 12-16, peroxide scavenger, i.e. antioxidant, component, in surface layer on gas diffusion backing; see e.g. Fan Paragraphs 0043, glue on outer surface of gas diffusion layer for gluing to catalyst layer), but does explicitly teach the bonding layer being in the form of a plurality of discontinuous dots. Fan does however teach that the bonding layer may be applied on only a portion of the surface, particularly dispensed uniformly, i.e. in lines, on the edges (see e.g. Fan Paragraph 0043, lines 2-3, and Paragraph 0083, lines 1-3).
Kohler teaches a process for manufacturing membrane electrode assemblies (see e.g. Abstract) comprising a step of providing an adhesive component such as an ionomer on a gas diffusion layer to be laminated with a catalyst-coated membrane (see e.g. Paragraph 0029 and Paragraph 0033, lines 1-8), wherein the adhesive may be applied in a pattern of thin lines or small dots at the corners and/or in the middle of the active area (see e.g. Paragraph 0034, lines 8-10).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the bonding layer of modified Ballantine to be in the form of discontinuous dots instead of lines as taught by Kohler as an alternate suitable pattern for applying an adhesive between a gas diffusion layer and catalyst-coated membrane of a membrane electrode assembly. MPEP § 2143(I)(B) states that “simple substitution of one known element for another to obtain predictable results” may be obvious.
Response to Arguments
Applicant’s arguments, see pages 7-10, filed 05/06/2026, with respect to the rejection(s) of amended claim(s) 1, 11 and 13 under 35 USC 103 over Buechi, particularly regarding the coating layers being directly on either side of the base layer having particles with an average size of 20-80 µm, have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Ballantine, Pushkarev and Buechi.
Conclusion
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/MOFOLUWASO S JEBUTU/Examiner, Art Unit 1795
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