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 .
Claim Rejections - 35 USC § 112
Applicant’s amendments to the claims have overcome the previously presented rejections under 35 U.S.C. 112(b) and thus the rejections are withdrawn.
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.
Claim(s) 5-7 and 10-11 are rejected under 35 U.S.C. 103 as being unpatentable over Kim1 (US 20240141520 A1) in view of Wittstadt (NPL – “Membrane electrode assemblies for unitized regenerative polymer electrolyte fuel cells”), Kim2 (US 20200208277 A1), Deng (US 20050205128 A1), Park (US 20200131657 A1), and Lee (NPL – “Development of porous Pt/IrO2/carbon paper electrocatalysts with enhanced mass transport as oxygen electrodes in unitized regenerative fuel cells”).
Regarding claim 5, Kim1 (US 20240141520 A1) teaches fabricating a membrane electrode assembly for polymer electrolyte membrane (PEM) water electrolysis by bonding an anode catalyst layer to one surface of the polymer electrolyte membrane and bonding a cathode catalyst layer to the other surface of the polymer electrolyte membrane by removing release films and hot pressing the films to the membrane (transferring anode electrode and cathode electrode to opposite surfaces of a polymer electrolyte membrane), wherein the anode electrode is formed by preparing an anode catalyst ink (slurry) comprising an ionomer (ion-conducting polymer) and iridium and ruthenium powder (anode catalyst) on a release film (transfer film), and wherein the cathode electrode is formed by preparing a cathode catalyst ink (slurry) comprising an ionomer (ion-conducting polymer) and amorphous carbon black containing platinum (cathode catalyst) on a release film (transfer film) (Abstract, para 0015-0023, 0057, 0064, 0081).
Kim1 fails to explicitly teach coating the anode electrode with platinum by sputtering to form a platinum layer on a surface of the anode electrode. However, Wittstadt (NPL), in the analogous art of membrane electrode assemblies, teaches a polymer electrolyte membrane device for use as a fuel cell or water electrolysis, wherein an additional layer of Pt is sputtered on the oxygen electrode (anode) after hot pressing the electrode to the membrane to improve efficiency of reversible fuel cell/water electrolysis operations, wherein the anode catalyst may comprise iridium powder (Abstract, pg. 556-558, 561; Fig. 3). Kim1 also teaches the membrane electrode assembly has an anode, or oxygen electrode, side comprising iridium catalyst and hot-pressed to the membrane (para 0017, 0081, 0091, 0119). It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to sputter a platinum layer on the outer surface of the anode electrode, as described by Wittstadt, to improve the efficiency of the membrane electrode assembly.
The combination of Kim1 and Wittstadt fails to explicitly teach the anode catalyst is iridium oxide. However, Kim2 (US 20200208277 A1), in the analogous art of membrane electrode assemblies, teaches an anode catalyst may be iridium, ruthenium, iridium oxide (IrO2), or a combination thereof, where the anode is formed by hot-pressing (para 0095, 0097, 0113, 0115). Kim1 teaches an anode formed by hot-pressing, where the anode catalyst is a mixture of iridium and ruthenium (para 0011, 0013, 0015, 0017, 0081). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to substitute the iridium and ruthenium anode catalyst of Kim1 with an iridium oxide (IrO2) anode catalyst, as described by Kim2, because this is a substitution of known elements yielding predictable results. See MPEP 2143(I)(B).
The combination of Kim1, Wittstadt, and Kim2 fails to explicitly teach the cathode catalyst is platinum-coated carbon powder. However, Deng (US 20050205128 A1), in the analogous art of membrane electrode assemblies, teaches a catalyst material may comprise Pt-coated carbon powder (para 0023, 0077). Kim1 teaches that the cathode catalyst may contain both Pt and carbon (para 0020). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to substitute the platinum and carbon containing catalyst of Kim1 with a Pt-coated carbon powder catalyst, as described by Deng, because this is a substitution of known elements yielding predictable results. See MPEP 2143(I)(B).
The combination of Kim1, Wittstadt, Kim2, and Deng fails to explicitly teach a thickness of the platinum layer formed by the sputtering ranges from 20 to 100 nm. However, Park (US 20200131657 A1), in the analogous art of water electrolysis, teaches an oxygen electrode (anode) comprising a Pt layer formed on a substrate and then coated by an iridium oxide catalyst layer such that the substrate is not exposed to iridium oxide, wherein the Pt layer may have a thickness of 10 nm to 500 nm (para 0018, 0042, 0046, 0058). Wittstadt teaches a Pt layer sputtered directly onto the membrane and in contact with a catalyst layer with a thickness of approximately 140 nm, wherein the same layer thickness may also be deposited on the outer anode surface (pg. 557-558; Fig. 3) but does not provide an acceptable range of thicknesses. Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to substitute the Pt thickness of Wittstadt with the Pt thickness of Park because this is a substitution of known elements yielding predictable results. See MPEP 2143(I)(B).
Though the combination of Kim1, Wittstadt, Kim2, Deng, and Park fails to explicitly teach a thickness within the range of 20 nm to 100 nm, one would have expected the use of any value within the Park range to have yielded similar results. Absent any showing of criticality, it would be obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have used any values within 10 nm to 500 nm, including values within the claimed range, with a reasonable expectation of success and with predictable results. Please see MPEP 2144.05 (I) for further details.
Alternatively, or in addition, Lee (NPL), in the analogous art of oxygen electrodes for water electrolysis, teaches that porous Pt layer may be disposed on the outside of an IrO2 catalyst layer where the thickness of Pt layers can influence the oxygen evolution reaction of the anode, especially negatively if the film is too thick (pg. 15-16), thus indicating the thickness is a result-effective variable influencing the anode efficiency. Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to determine the optimum or workable ranges of Pt thickness by routine optimization, which can include a thickness of 20 nm to 100 nm. See MPEP 2144.05(II).
Regarding claim 6, the combination of Kim1, Wittstadt, Kim2, Deng, Park, and Lee teaches the anode catalyst is iridium oxide (Kim2 para 0095, 0097, 0115).
Regarding claim 7, the combination of Kim1, Wittstadt, Kim2, Deng, Park, and Lee teaches the cathode catalyst is platinum coated carbon powder (Deng para 0023, 0077).
Regarding claim 10, the combination of Kim1, Wittstadt, Kim2, Deng, Park, and Lee teaches the platinum layer is formed by sputtering in an argon atmosphere (argon sputtering) (Wittstadt pg. 557-558).
Regarding claim 11, the combination of Kim1, Wittstadt, Kim2, Deng, Park, and Lee teaches the ionomer (ion-conducting polymer) used in each of the anode catalyst slurry and cathode catalyst slurry may be a fluorocarbon based ionomer such as Nafion (cation-conducting ionomer) (Kim1 para 0057).
Response to Arguments
Applicant's arguments filed 12/31/2025 have been fully considered but they are not persuasive.
Applicant argues that evidence of unexpected results is provided in the specification and cites to paragraphs 0071-0083. This argument is not persuasive because the data provided in the specification include an example with a platinum layer 80 nm thick (MEA2), an example with a platinum layer 40 nm thick (MEA3), a comparative example with no platinum layer (MEA1), and a comparative example with only a platinum layer and no iridium oxide catalyst layer (MEA4), which at best demonstrates that a platinum layer results in improved performance when compared to no platinum layer. However, Wittstadt teaches depositing a platinum layer of a different thickness on the anode which improves performance (see pg. 558) and the specification provides no evidence that a film thickness within the claimed range produces unexpectedly better results when compared to other thicknesses outside of the claimed range (e.g., 10 nm or 140 nm).
Applicant also submits additional experimental data/graphs showing different thicknesses of platinum and their effects on various properties allegedly indicating that excellent performance was achieved when the thickness is 20 to 120 nm while a less pronounced effect was achieved at 200 nm. These arguments are not persuasive for several reasons. First, the new data provided was not present in the original specification and evidence of unexpected results must be supported by an appropriate affidavit or declaration (See MPEP 716.01(c)). Second, the data provided does not include the thickness of 140 nm included in Wittstadt and therefore it is unclear if the results are truly unexpected or just a trend of decreasing efficacy as the thickness increases. Lastly, the new data allegedly describes that the 20 to 120 nm range produces the best results, which appears to conflict with the argument that the claimed range of 20 to 100 nm provides unexpected results because 120 nm would also produce these “unexpected results” and thus the unexpected results would not be commensurate in scope with the claims. It should also be noted that the data provided is in black and white and thus it is difficult to fully evaluate which data refers to each thickness, which could be resolved by including different shapes or types of lines (e.g., dotted, dashed, etc.).
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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/PATRICK S OTT/Examiner, Art Unit 1794