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 .
Response to Amendments
This is a final office action in response to applicant's arguments and remarks filed on 12/18/2025.
Status of Rejections
The objections to the claims are withdrawn in view of applicant’s amendments.
All previous rejections are withdrawn in view of applicant’s amendments.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 1-2, 4, 11-14, 16 and 19-20 are rejected under 35 U.S.C. 103 as being unpatentable over Buechi et al. (U.S. 2022/0085390).
Regarding claim 1, Buechi teaches a porous transport layer (see e.g. Fig. 2, multilayer porous transport layer (PTL) 2; Paragraph 0027, lines 1-2, and Paragraph 0031, lines 1-2) comprising:
a base layer comprising a titanium family element (see e.g. Fig. 2, porous support layer 4 and one or both of microporous layer 8 and nanoporous layer 10 comprising conductive material such as titanium; Paragraph 0008, lines 1-3, Paragraph 0018, and Paragraph 0032, lines 2-4);
a first coating layer disposed on a first surface of the base layer, wherein the first coating layer comprises iridium (see e.g. Fig. 2, top protective layer 12 comprising Ir provided on final MPL 8 or NPL 10; Paragraph 0034, lines 4-8), and wherein the first coating layer has an average thickness of in a range from 0.02 to 2 µm (see e.g. Paragraph 0034, lines 5-7), overlapping the claimed range of the present invention; and
a second coating layer disposed on a second, opposite surface of the base layer, wherein the second coating layer comprises platinum, gold, or combinations thereof (see e.g. Fig. 2, bottom protective layer 12 comprising Pt, Au and alloys thereof provided on support layer 4; Paragraph 0034, lines 4-9).
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, Buechi teaches the titanium family element comprising titanium (see e.g. Paragraph 0018).
Regarding claim 4, Buechi teaches the base layer having an average thickness in a range from 402 to 733 µm (see e.g. Paragraph 0031, lines 2-4, Paragraph 0032, line 8, and Paragraph 0033, lines 4-5, support layer with exemplary thickness of 0.4 mm, equal to 400 µm, with one or both of MPL with thickness of 10-300 µm and NPL with thickness of 2 to 30 µm); and
the second coating layer having an average thickness in a range from 0.02 to 2 µm (see e.g. Paragraph 0034, lines 5-7), overlapping the claimed range of the present invention (see MPEP § 2144.05 I as cited above).
Regarding claim 11, Buechi teaches a water electrolysis cell (see e.g. Paragraph 0034, lines 24-31, and Paragraph 0002, lines 1-2, assembled electrochemical cell for polymer electrolyte water electrolysis (PEWE)) comprising:
a porous transport layer (see e.g. Fig. 2, multilayer porous transport layer (PTL) 2; Paragraph 0027, lines 1-2, and Paragraph 0031, lines 1-2) comprising:
a base layer comprising a titanium family element (see e.g. Fig. 2, porous support layer 4 and one or both of microporous layer 8 and nanoporous layer 10 comprising conductive material such as titanium; Paragraph 0008, lines 1-3, Paragraph 0018, and Paragraph 0032, lines 2-4);
a first coating layer disposed on a first surface of the base layer, wherein the first coating layer comprises iridium (see e.g. Fig. 2, top protective layer 12 comprising Ir provided on final MPL 8 or NPL 10; Paragraph 0034, lines 4-8), and wherein the first coating layer has an average thickness of in a range from 0.02 to 2 µm (see e.g. Paragraph 0034, lines 5-7), overlapping the claimed range of the present invention (see MPEP § 2144.05 I as cited above); and
a second coating layer disposed on a second, opposite surface of the base layer, wherein the second coating layer comprises platinum, gold, or combinations thereof (see e.g. Fig. 2, bottom protective layer 12 comprising Pt, Au and alloys thereof provided on support layer 4; Paragraph 0034, lines 4-9).
Regarding claim 12, Buechi teaches an anode bipolar plate disposed on the second coating layer of the porous transport layer (see e.g. Fig. 2, bipolar plate contacting protective layer 12 on the side of the porous support layer 4; Paragraph 0034, lines 26-28); and
a membrane-electrode assembly disposed on the first coating layer (see e.g. Fig. 2, catalyst layers forming electrodes and subsequent polymer membrane, i.e. MEA, sandwiched on the protective layer 12 on the side of the nanoporous layer 10 and/or microporous layer 8; Paragraph 0034, lines 22-26, and Paragraph 0002, lines 10-14).
Regarding claim 13, Buechi teaches a method for preparing a porous transport layer (see e.g. Fig. 2, provided multilayer porous transport layer (PTL) 2; Paragraph 0027, lines 1-2, and Paragraph 0031, lines 1-2), the method comprising:
stacking a first coating layer containing iridium on a first surface of a base layer (see e.g. Fig. 2, top protective layer 12 comprising Ir provided on final MPL 8 or NPL 10; Paragraph 0034, lines 4-8), wherein the base layer comprises a titanium family element (see e.g. Fig. 2, porous support layer 4 and one or both of microporous layer 8 and nanoporous layer 10 comprising conductive material such as titanium; Paragraph 0008, lines 1-3, Paragraph 0018, and Paragraph 0032, lines 2-4), and wherein the first coating layer has an average thickness of in a range from 0.02 to 2 µm (see e.g. Paragraph 0034, lines 5-7), overlapping the claimed range of the present invention (see MPEP § 2144.05 I as cited above); and
stacking a second coating layer on a second, opposite surface of the base layer, wherein the second coating layer comprises platinum, gold, or combinations thereof (see e.g. Fig. 2, bottom protective layer 12 comprising Pt, Au and alloys thereof provided on support layer 4; Paragraph 0034, lines 4-9).
Regarding claim 14, Buechi teaches the titanium family element comprising titanium (see e.g. Paragraph 0018).
Regarding claim 16, Buechi teaches each coating layer of the first coating layer and the second coating layer being independently formed using a spray coating method (see e.g. Paragraph 0034, lines 5-7, plasma spray coating).
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.”. Buechi 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.
Claims 3 and 15 are rejected under 35 U.S.C. 103 as being unpatentable over Buechi in view of Wang et al. (CN 115216798 A, citations based on translation).
Regarding claims 3 and 15, Buechi teaches all the element of the porous transport layer of claim 1 and method of claim 13 as stated above. Buechi does not explicitly teach the second coating layer further comprising ruthenium (Ru), palladium (Pd), rhodium (Rh), osmium (Os), or combinations thereof, but it generally comprising an inert metal or alloy of metals such as Pt, Ir and Au (see e.g. Paragraph 0019, lines 4-6) and being a corrosion protective coating for suppressing frown of Ti oxide layers (see e.g. Paragraph 0034, lines 1-4).
Wang teaches an anode gas diffusion layer for membrane electrode water electrolysis (see e.g. Abstract) comprising a protective precious metal coating provided on a titanium substrate to make it less susceptible to oxidation and corrosion (see e.g. Paragraph n0010, lines 3-7, and Paragraph n0012, lines 1-2), the protective precious metal coating comprising at least one of platinum, gold, iridium, palladium, rhodium and osmium (see e.g. Paragraph n0012, lines 3-4, Paragraph n0024 and Claim 1).
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 Buechi to further comprise at least one of palladium, rhodium and osmium as taught by Wang as additional metals that can be used with Pt, Ir and Au in a protective coating for making a titanium substrate less susceptible to oxidation and corrosion. 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.
Claims 5-6 and 17 are rejected under 35 U.S.C. 103 as being unpatentable over Buechi in view of Siddiqui et al. (U.S. 2007/0213209).
Regarding claim 5, Buechi teaches all the elements of the porous transport layer of claim 1 as stated above. Buechi 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. Buechi does however teach the first coating layer being sandwiched with an electrode catalyst layer when the porous transport layer is assembled into an electrochemical cell such as a fuel cell (see e.g. Fig. 2, top protective coating 12 on side of nanoporous layer 10 adjacent catalyst layer in electrochemical cell; Paragraph 0034, lines 22-31, and Paragraph 0002).
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 Buechi 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 a cell as taught by Siddiqui to increase the hydrogen peroxide radical resistance of the assembled cell.
Regarding claim 6, Buechi 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, Buechi teaches all the elements of the method of claim 13 as stated above. Buechi 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. Buechi does however teach the first coating layer being sandwiched with an electrode catalyst layer when the porous transport layer is assembled into an electrochemical cell such as a fuel cell (see e.g. Fig. 2, top protective coating 12 on side of nanoporous layer 10 adjacent catalyst layer in electrochemical cell; Paragraph 0034, lines 22-31, and Paragraph 0002).
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 Buechi 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 Buechi in view of 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 Buechi teaches all the elements of the porous transport layer of claim 5 as stated above. Modified Buechi 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. Buechi as modified by Siddiqui does however teach Buechi does however teach the first coating layer being sandwiched with an electrode catalyst layer when the porous transport layer is assembled into a membrane electrode electrochemical cell such as a fuel cell (see e.g. Buechi Fig. 2, top protective coating 12 on side of nanoporous layer 10 adjacent catalyst layer in electrochemical cell; Paragraph 0034, lines 22-31, and Paragraph 0002), 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 Buechi 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, Buechi 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 Buechi teaches all the elements of the method of claim 17 as stated above. Modified Buechi 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. Buechi as modified by Siddiqui does however teach Buechi does however teach the first coating layer being sandwiched with an electrode catalyst layer when the porous transport layer is assembled into a membrane electrode electrochemical cell such as a fuel cell (see e.g. Buechi Fig. 2, top protective coating 12 on side of nanoporous layer 10 adjacent catalyst layer in electrochemical cell; Paragraph 0034, lines 22-31, and Paragraph 0002), 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 Buechi 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 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 Buechi teaches all the elements of the porous transport layer of claim 7 as stated above. Modified Buechi 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 Buechi 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 Buechi teaches all the elements of the porous transport layer of claim 7 as stated above. Buechi 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 Buechi 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 filed 12/18/2025 have been fully considered but they are not all persuasive.
On pages 8-9, Applicant argues that Buechi does not disclose the claimed structure because it includes intermediate layers between the base/support layer and the protective layer. This is not considered persuasive. The claim only requires “a base layer comprising a titanium family element”. There are no other specific limitations placed on the claimed “base layer” nor is a special definition provided for it in the specification. Buechi teaches support layer and microporous/nanoporous layers or the multilayer porous transport layer structure comprising titanium (see e.g. Paragraph 0007, Paragraph 0008, lines 1-3, Paragraph 0018, and Paragraph 0032, lines 2-4). Therefore, regardless of how they are separately labelled in Buechi, the combination of the support layer and microporous/nanoporous layers of Buechi meets the claimed limitation of a “base layer” on which the first and second coating layers are provided.
On page 9, Applicant argues that Buechi does not disclose or suggest an iridium first coating layer having an average thickness in a range from 1-10 micrometers. This is not considered persuasive. Buechi teaches the first coating layer comprising iridium (see e.g. Paragraph 0034, lines 4-5), as required by the claim. The claim does not require the first coating layer be only iridium, as “comprising” is an open transitional word. Regardless, even if the first coating layer were required to consist of iridium, Buechi still teaches iridium being one of a finite list of exemplary materials to be used in the coating layer (see e.g. Paragraph 0034, lines 4-5, Pt, Ir and Au). MPEP § 2143 I (E) states that it may be obvious to choose “from a finite number of identified, predictable solutions, with a reasonable expectation of success”. Regarding the thickness limitation, though Buechi does not disclose a specific example anticipating the range, it does teach the coating layer having a thickness in a range of 0.02 to 2 µm (see e.g. Paragraph 0034, lines 5-7), overlapping the claimed range. 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.”
Applicant’s arguments, see page 9, filed 12/18/2025, with respect to the rejection(s) of amended claim(s) 1, 11 and 13 under 35 USC 102 over Buechi, particularly regarding the anticipation of the coating layer thickness, 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 Buechi under 35 USC 103.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Skoczylas et al. (U.S. 2005/0142402) discloses an electrochemical cell using a porous electrode structure comprising a catalyst on a porous support that shows a voltage degradation of less than 1 microvolt per cell hour over a period of over 1600 hours and has a current density of 1000 A/cm2 at a voltage of ~2.78V.
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MOFOLUWASO S JEBUTU whose telephone number is (571)272-1919. The examiner can normally be reached M-F 9am-5pm.
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/M.S.J./Examiner, Art Unit 1795
/LUAN V VAN/Supervisory Patent Examiner, Art Unit 1795