DETAILED ACTION
Notice of Pre-AIA or AIA Status
1. 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
2. The applicant’s response dated 07 November 2025 have been entered into the record and is considered fully responsive. The examiner notes that the class of invention has been amended as per the interview conducted with the applicant on 07 November 2025. Claims 1, 2, 3, 4, 5, 6, 7 are pending and under examination. The applicant cancelled Claim 8, 9, 10, 11, 12, 13, and 14. The applicant has included amended drawings in response to the objection raised by the examiner in the office action dated 11 August 2025, but it appears that have submitted drawings not pertinent to the instant application.
Drawings
3. New corrected drawings are required for the instant application. The amended drawings submitted on 07 November 2025 appear to be for a different application (i.e.: not the instant application). Based on the specification and the original drawings submitted, there should be figured labeled up to 18B. The corrected drawings are required in reply to the Office action to avoid abandonment of the application. The requirement for corrected drawings will not be held in abeyance.
Claim Rejections - 35 USC § 103
4. 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.
5. 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.
6. Claims 1, 3, and 7 are rejected under 35 U.S.C. 103 as being unpatentable over Arimoto in view of Park et al.
Arimoto (JP2008156684A) is a patent publication directed toward an electrode for hydrochloric acid electrolysis, which is an oxidative process where chloride is converted to chlorine and/or chlorine (title). Park et al. (“Electrodeposition of High-Surface-Area IrO2 Films on Ti Felt as an Efficient Catalyst for the Oxygen Evolution Reaction,” Frontiers in Chem. 2020, 8, article 593272, pg. 1-9) is directed toward electrodeposited iridium oxide films for OER (pg. 1: title).
Regarding Claim 1, Arimoto discloses a method for driving a water electrolysis device with an oxidizing electrode or an anode which catalyzes oxidative processes such as the formation of chlorine (and chlorine oxides) from chloride (¶2, 13, and 16) or the formation of oxygen from water as IrO2 is a well-known OER catalyst. Arimoto explicitly discloses the formation of an intermediate ruthenium layer which is applied via electrodeposition onto a titanium substrate in example 3 (¶22). Arimoto further teaches a catalyst layer comprised of iridium oxide as indicated in example 3 (¶22). Arimoto et al. indicates that this coating procedure can be applied repeatedly (i.e.: “repeatedly in an alternating manner”) in ¶22. However, the catalyst layer of Arimoto is applied using thermal decomposition of a soluble iridium precursor as opposed to electrodeposition. Therefore, Arimoto does not teach application of an iridium oxide layer using electrodeposition.
Park et al. teaches a method of electrodepositing IrO2 onto titanium felt after various etching times for use as an OER anode (pg. 1: abstract). OER is an oxidative process where each hydroxide ion (oxide oxidation state = 2-) loses two electrons to form oxygen atoms which combine into dioxygen (oxygen oxidation state = 0). According to Park et al., etching the titanium felt resulted in the deposition of a uniform amorphous IrO2 film (pg. 1: Abstract; pg. 4: Results and Discussion; and pg. 7: Conclusion). Appropriate surface etching results in good substrate adhesion and a quality catalyst layer (pg. 2: Introduction). Moreover, Park et al. indicates that the deposition of an iridium oxide layer improves the corrosion resistance (of the titanium) substrate in acidic electrolyte, such as perchloric acid (pg. 7: Discussion).
It would be obvious to one ordinary skill in the art prior to the effective filing date of the claimed invention to modify (the method of making) the titanium/ruthenium/iridium oxide electrode of Arimoto by using an etched titanium felt and an electrodeposited IrO2 layer as taught by Park et al. Forming an electrode comprised of etched titanium felt substrate, an electrodeposited ruthenium intermediate layer, and an electrodeposited iridium oxide catalyst layer would reasonably results in oxidation electrode that has improved corrosion resistance in acidic electrolyte given the ruthenium and iridium oxide layers.
The amendment to Claim 1 have specified both the current density and the application time for the both the electrodeposition of Ru and IrO2. Pertaining to Ru deposition, Arimoto discloses the use of a Ru bath comprising 10 g/L ruthenium with a deposition time of 30 minutes at a current density of 0.5 A/dm2 (¶22). Pertaining to IrO2 deposition, Park et al. discloses the use of a bath of 0.1 M iridium with a deposition time of 10 minutes as a current density of 2.5 mA/cm2.
One of ordinary skill in the art of plating would understand that the factors that dictate the deposition Ru or IrO2. The factors that are most important are the concentration (or Ru or Ir), applied current density, and deposition time. The use of elevated concentrations of precious metals (i.e.: Ru or Ir) present in a plating bath is a significant cost to the user, so reduction of said precious metal concentration would provide an economic advantage. The reduction in deposition rate of precious metal (from a reduced concentration) can be overcome by increasing the current density and/or deposition time. Therefore, the deposition time and current density are result-effective variables, i.e., variables which achieve recognized results, and the determination of the optimum or workable ranges of said variables might be characterized as routine experimentation (See MPEP 2144.0.II.B.). Accordingly, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have discovered the optimum or workable ranges of the deposition time and current density for Ru and iridium oxide, including values within the claimed range, through routine experimentation. One would have been motivated to do so in order to have formed an electrode with an intermediate Ru (oxide) layer and an iridium oxide catalyst layer which has sufficient corrosion resistance and higher catalytic activity in a corrosive electrolyte while minimizing the cost of said coating layer by reducing the precious metal concentration in the plating baths.
Regarding Claim 3, Arimoto in view of Park et al. et al. discloses the method of Claim 1 with an oxidizing electrode, wherein the thickness of the iridium oxide layer ranges from 157 to 201 nm (Park on pg. 6: Results and Discussion) which was derived from the mass loading of IrO2. Park et al. discloses a range of 0.183 mg/cm2 of IrO2 to 0.234 mg/cm2 of IrO2 depending on the etching time. The mass loading is converted to the thickness using the density of iridium oxide (ρIrOx = 11.66 g/cm3) with a sample calculation in the box below.
Thickness of IrO2 Layer derived from Mass Loading of IrO2 – Sample Calculation
0.183 mg/cm2 x (1 cm3/11.66 g) x (1g/1000 mg) x (107 nm/1cm) = 157 nm thick IrO2 layer
Regarding Claim 7, Arimoto in view of Park et al. discloses the method of Claim 1 with an oxidizing electrode, wherein the substrate is titanium felt (analogous to titanium paper of the present application) that is comprised of titanium fibers as evidenced by the SEM images of Park et al. (Fig. 7A and Fig. 7D). In said SEM images, the pristine titanium felt and individual fibers having a width of ~22 microns are clearly shown (pg. 4-5: Results and Discussion – for fiber width).
7. Claims 2, 5, and 6 are rejected under 35 U.S.C. 103 as being unpatentable over Arimoto in view of Park et al. as applied to Claim 1 above, and further in view of Joo et al.
Arimoto (citation above) is a patent publication directed toward an electrode for hydrochloric acid electrolysis, which is an oxidative process where chloride is converted to chlorine and/or chlorine (title). Park et al. (citation above) is directed toward electrodeposited iridium oxide films for OER (pg. 1: title). Joo et al. (WO2005050721A1) is a patent publication directed toward the electrodeposition of ruthenium oxide for use in acid electrolyte capacitors (abstract).
Regarding Claim 2, Arimoto in view of Park et al. discloses the method with an oxidizing electrode as per Claim 1. Arimoto discloses the thickness of 500 nm to 10 microns for the thickness of the intermediate layer of ruthenium which provides corrosion resistance to the oxidizing electrode (¶10-11). Moreover, Park et al. is silent on the use of an intermediate ruthenium layer in an oxidation electrode. Therefore, Arimoto in view of Park et al. does not teach the thickness of the ruthenium layer as ranging from 140 to 154 nm in thickness.
Joo et al. is directed toward the anodic electrodeposition of thin ruthenium oxide films (pg. 3: lines 6-10). The deposition occurs onto a conductive substrate such as a titanium plate (pg. 4: lines 2-5). The deposition electrolyte is comprised of a ruthenium salt (pg. 3: lines 18-20) without a chelating agent (pg. 3 and 4: lines 27 and 1). The thickness of the deposited ruthenium oxide layer ranges from 100 nm to 20 microns. (pg. 4: lines 21-25). Joo et al. discloses the deposited ruthenium oxide layers have stability in sulfuric acid electrolytes under applied voltage as said materials are effective capacitors (pg. 6: lines 7-19). As evidenced by at least the teachings in the introduction of Park et al. (pg. 1-2) indicated that RuO2 is a very active OER catalyst, the ruthenium oxide film of Joo et al. is capable of having the same activity.
Therefore, it would be obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify method including the oxidation electrode disclosed by Arimoto et al. in view of Park by using the thin film ruthenium oxide layer taught by Joo et al. as the interlayer (in place of the electrodeposited metallic ruthenium layer) with the reasonable expectation of forming an oxidation electrode that has increased corrosion resistance and is an efficient OER catalyst in an acidic electrolyte with the combination of RuO2 and IrO2.
Regarding Claim 5, Arimoto in view of Park et al. discloses the method of Claim 1 with an oxidizing electrode. Arimoto discloses the thickness of 500 nm to 10 microns for the thickness of the intermediate layer of ruthenium which provides corrosion resistance to the oxidizing electrode (¶10-11) and does not specify the coating weight of the deposited Ru. Moreover, Park et al. is silent on the use of an intermediate ruthenium layer in an oxidation electrode. Therefore, Arimoto in view of Park et al. does not teach the coating weight of the intermediate ruthenium layer as ranging from 0.01 to 0.06 mg/cm2.
Joo et al. is directed toward the anodic electrodeposition of thin ruthenium oxide films (pg. 3: lines 6-10). The deposition occurs onto a conductive substrate such as a titanium plate (pg. 4: lines 2-5). The deposition electrolyte is comprised of a ruthenium salt (pg. 3: lines 18-20) without a chelating agent (pg. 3 and 4: lines 27 and 1). The thickness of the deposited ruthenium oxide layer ranges from 100 nm to 20 microns. (pg. 4: lines 21-25). Joo et al. discloses the deposited ruthenium oxide layers have stability in sulfuric acid electrolytes under applied voltage as said materials are effective capacitors (pg. 6: lines 7-19). As evidenced by at least the teachings in the introduction of Park et al. (pg. 1-2) indicated that RuO2 is a very active OER catalyst, the ruthenium oxide film of Joo et al. is capable of having the same activity.
Therefore, it would be obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify the oxidation electrode disclosed by Arimoto et al. in view of Park by using the thin film ruthenium oxide layer taught by Joo et al. as the interlayer (in place of the electrodeposited metallic ruthenium layer) with the reasonable expectation of forming an oxidation electrode that has increased corrosion resistance and is an efficient OER catalyst in an acidic electrolyte with the combination of RuO2 and IrO2.
The combination of Arimoto, Park et al., and Joo et al. disclose the use of a thin ruthenium oxide interlayer with a thickness ranging from 100 nm to 20 microns, but does not indicate the coating weight of said thin layer. However, the thickness and coating weight are correlated meaning coating weight is a result-effective variables, i.e., a variable which achieve recognized results, and the determination of the optimum or workable ranges of said variable might be characterized as routine experimentation (See MPEP 2144.0.II.B.). Accordingly, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have discovered the optimum or workable ranges of Ru coating weight, including values within the claimed range, through routine experimentation. One would have been motivated to do so in order to have formed an electrode with an intermediate Ru (oxide) layer to provide sufficient corrosion resistance and higher catalytic activity in a corrosive electrolyte.
Regarding Claim 6, Arimoto in view of Park et al. discloses the method of Claim 1 with an oxidizing electrode. Arimoto discloses the thickness of 500 nm to 10 microns for the thickness of the intermediate layer of ruthenium which provides corrosion resistance to the oxidizing electrode (¶10-11) and does not specify the coating weight of the deposited Ru. Moreover, Park et al. is silent on the use of an intermediate ruthenium layer in an oxidation electrode. Therefore, Arimoto in view of Park et al. does not teach the total coating weight of Ru and IrO2 layer as ranging from 0.05 to 0.11 mg/cm2.
Joo et al. is directed toward the anodic electrodeposition of thin ruthenium oxide films (pg. 3: lines 6-10). The deposition occurs onto a conductive substrate such as a titanium plate (pg. 4: lines 2-5). The deposition electrolyte is comprised of a ruthenium salt (pg. 3: lines 18-20) without a chelating agent (pg. 3 and 4: lines 27 and 1). The thickness of the deposited ruthenium oxide layer ranges from 100 nm to 20 microns. (pg. 4: lines 21-25). Joo et al. discloses the deposited ruthenium oxide layers have stability in sulfuric acid electrolytes under applied voltage as said materials are effective capacitors (pg. 6: lines 7-19). As evidenced by at least the teachings in the introduction of Park et al. (pg. 1-2) indicated that RuO2 is a very active OER catalyst, the ruthenium oxide film of Joo et al. is capable of having the same activity.
Therefore, it would be obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention to modify the method including the oxidation electrode disclosed by Arimoto et al. in view of Park by using the thin film ruthenium oxide layer taught by Joo et al. as the interlayer (in place of the electrodeposited metallic ruthenium layer) with the reasonable expectation of forming an oxidation electrode that has increased corrosion resistance and is an efficient OER catalyst in an acidic electrolyte with the combination of RuO2 and IrO2.
The combination of Arimoto, Park et al., and Joo et al. disclose the use of a thin ruthenium oxide interlayer with a thickness ranging from 100 nm to 20 microns, but does not indicate the coating weight of said thin layer nor the total coating weight of the catalyst layer (i.e. Ru + IrO2). However, the thickness and coating weight are correlated meaning the (total) coating weight is a result-effective variable, i.e., a variable which achieve recognized results, and the determination of the optimum or workable ranges of said variable might be characterized as routine experimentation (See MPEP 2144.0.II.B.). Accordingly, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have discovered the optimum or workable ranges of the total coating weight, including values within the claimed range, through routine experimentation. One would have been motivated to do so in order to have formed an electrode with an intermediate Ru (oxide) layer and IrO2 upper layer to provide sufficient corrosion resistance and higher catalytic activity in a corrosive electrolyte.
8. Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Arimoto in view of Park et al. as applied to Claim 1 above, and further in view of Kim et al.
Arimoto (citation above) is a patent publication directed toward an electrode for hydrochloric acid electrolysis, which is an oxidative process where chloride is converted to chlorine and/or chlorine (title). Park et al. (citation above) is directed toward electrodeposited iridium oxide films for OER (pg. 1: title). Kim et al. (KR20210034900A) is a patent publication directed toward anode catalysts comprising metal oxides for water splitting (abstract).
Regarding Claim 4, Arimoto in view of Park et al. disclose the method of Claim 1 with the oxidizing electrode having ruthenium as an intermediate layer and iridium oxide as the catalyst layer, but is silent on the specific surface area of the deposited iridium oxide. The oxidation electrode of Claim 1 (i.e.: the anode) comprising a titanium felt substrate, an electrodeposited intermediate ruthenium layer, and an electrodeposited iridium oxide catalyst is capable of catalyzing oxygen evolution reaction as evidenced by at least the introduction of Park et al. on pg. 1-2.
Kim et al. is directed toward iridium oxide (and/or titanium oxide) anodes for application in water electrolysis devices (¶1). Kim et al. further discloses the specific surface area of iridium oxide catalysts to range from 10 to 20 m2/g as measured by BET to ensure there is no reduction in catalytic reaction activity (¶40). The synthesized iridium oxide is discussed in comparative example 1-2 (¶109-110) and the process of preparing said material requires heating at 500 oC for one hour (¶60). The annealing process results in (partial) crystallization and particle growth which both reduce the surface area of the iridium oxide. The iridium oxide of comparative example 1-2 when incorporated into a full membrane electrode assembly provides stable voltage over time like the inventive examples in Kim et al. as indicated in ¶187.
It would be obvious to one ordinary skill in the art prior to the effective filing date of the claimed invention to modify the titanium/ruthenium/iridium oxide electrode of Arimoto in view of Park et al. by applying an annealing step to the electrode to set the specific surface area of the iridium oxide layer as taught by Kim et al. with the reasonable expectation of forming an efficient OER catalyst with long term stable electrical performance (Kim et al. in ¶187).
Therefore, the combination of Arimoto, Park et al. and Kim et al. disclose a specific surface area (as measured by BET) of 10 m2/g to 20 m2/g of iridium oxide to ensure efficient catalytic activity (¶8 and ¶40). A prima facie case of obviousness exists when the range disclosed in the prior art overlap with the claimed range (e.g.: the specific surface area of the iridium oxide). See MPEP 2144.05(I) - OVERLAPPING, APPROACHING, AND SIMILAR RANGES, AMOUNTS, AND PROPORTIONS.
Response to Arguments
9. As noted above, the applicant appears to have submitted incorrect amended drawing on 07 November 2025 so the previous objection has not been withdrawn.
10. Applicant’s arguments, see pg. 6-7, filed 07 November 2025, with respect to the rejection(s) of claim(s) 1, 2, 3, 4, 5, 6, and 7 under 103 have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection have been presented above.
Claims 1, 3, and 7 has been rejected as being obvious in view of Arimoto and Park et al. The combination of references clearly teaches a catalyst layer comprised of a Ru intermediate layer (applied directly to the substrate) and an IrOx layer applied to the Ru intermediate layer using electroplating or electrodeposition. The amendment to Claim 1 where the deposition time and current density are specified are two parameters known to be required to be optimized by one of ordinary skill in the art for any plating process, so given the composition disclosed by Arimoto and Park et al., Claim 1 is obvious.
Claims 2, 5, and 6 has been rejected as being obvious in view of Arimoto, Park et al. and Joo et al. Arimoto and Claim 4 has been rejected as being obvious in view of Arimoto, Park et al., and Kim et al. Specific reasons for said rejections are discussed above.
Conclusion
11. 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.
12. Any inquiry concerning this communication or earlier communications from the examiner should be directed to KEVIN SYLVESTER whose telephone number is (703)756-5536. The examiner can normally be reached Mon - Fri 8:15 AM to 4:30 PM EST.
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/KEVIN SYLVESTER/Examiner, Art Unit 1794
/JAMES LIN/Supervisory Patent Examiner, Art Unit 1794