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 Amendment
2. The amendments filed 17 February 2026 have been entered into the record. The examiner finds that the amendment to Claim 1 and Claim 3 have basis in the originally filed specification as indicated by the applicant in their response. New Claim 19 was added by the applicant and no new matter was added. Claims 2, 4, and 5 were previously cancelled by the applicant. Claims 1, 3, 6, 7, 8, 9, and 19 are pending and under examination.
Claim Rejections - 35 USC § 103
3. 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.
4. 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.
5. Claims 1, 3, 6, 7, 8, and 9 are rejected under 35 U.S.C. 103 as being unpatentable over Scott et al. in view of Gong et al.
Scott et al. (“Physical and Electrochemical Evaluation of ATO supported IrO2 Catalyst for Proton Exchange Membrane Water Electrolyzer,” J. Power Sources 2014, 269, 451-460) is directed toward an IrO2 catalyst shell on a ATO core (pg. 451: abstract). Gong et al. (“Recent Advances in Earth-Abundant Core/Noble-Metal Shell Nanoparticles for Electrocatalysis,” ACS Catal. 2020, 10, 10886-10904) is directed toward optimization of core-shell electrocatalysts (pg. 10886: abstract).
Regarding Claim 1, Scott discloses a method of making a water electrolysis catalyst (pg. 452: 2.1. Catalyst Preparation section) using a modified Adams fusion method. Scott et al. discloses depositing a substantially continuous thin shell layer of a platinum group metal (PGM)-based precursor (i.e.: H2IrCl6) on a nano-sized (i.e.: 22-44 nm particle size) inorganic oxide core (i.e.: antimony-doped tin oxide, “ATO”) to form a coated inorganic oxide core (i.e.: IrO2 on ATO) as supported IrO2 forming a continuous electronic network (pg. 459: Conclusion section). The Catalyst Preparation Section of Scott et al. further discloses preparing a H2IrCl6 solution in isopropanol followed by dispersing an amount of ATO support (i.e.: the inorganic core) according to the stoichiometry to obtain the required IrO2 loading (weight %) on the support (pg. 452) resulting in the deposition of a continuously thin shell of PGM-precursor prior to further processing. The next step of the method of Scott et al. was adding excess NaNO3 (i.e.: the template) and then removing the solvent (i.e.: drying). The dried mixture was then calcined at 500 degrees C for 1 h in a muffle furnace to convert the substantially continuous thin shell layer of the PGM-based precursor (iridium nitrates and/or chlorides) to a substantially continuous thin shell layer of PGM oxide (i.e.: IrO2) as per pg. 452: 2.1. Catalyst Preparation section. Lastly, Scott et al. discloses removing the template via washing with water to form the water electrolysis catalyst comprising the nano-sized inorganic oxide core having the substantially continuous thin shell layer of the PGM oxide.
There are two differences between the method of Scott et al. and the limitations of amended Claim 1, which can be rendered obvious by one of ordinary skill.
First, the method of Claim 1 has the limitation of a continuously PGM oxide layer/shell with metal oxide loading of less than 30 wt.%. Scott et al. explicitly discloses a range of IrO2 oxide from 20 wt.% to 90 wt.% on ATO showing that all catalyst loadings have improved electrical conductivity (Scott et al. on pg. 458: Table 3) and electrochemical activity (Scott et al. on pg. 458: Fig. 10 and Fig. 11) over the uncoated control. However, Scott et al. indicated that higher catalyst loadings result in a continuous shell IrO2 shell as evidenced by an electrical conductivity which approaches pure IrO2 (4.9 S/cm in pg. 454: Table 1). In order to effectively improve the shell coverage of the core at lower catalysts loadings (e.g.: 20 wt.% IrO2), one of ordinary skill in the art would reduce the particle size of the core material. The ATO inorganic core of Scott et al. was approximately 33 nm in size, but reducing the size of the inorganic core while holding the catalyst loading constant (e.g.: 20 wt.%) would be expected to result in greater coverage of the surface area of the inorganic core by the shell. The resultant shell would more uniformly and completely cover the inorganic core. Decreasing the particle size of the core at 20 wt.% IrO2 would reasonably be expected to results in improve electrical conductivity and enhanced catalytic activity.
Support for the aforementioned rationalization can be found in Gong et al., which is analogous art to Scott et al. because both references are directed toward the synthesis of core-shell materials having a PGM (oxide) used for electrocatalysis. In the chemical review, Gong et al. cited a study that demonstrated a micron-sized (WC) core material covered by a Pt catalyst had comparable activity to the control Pt/C catalyst at a 10x reduction in the catalyst loading (pg. 10896: bottom of page in section 4.3. Carbide Core). Stemming from this observation, Gong et al. suggests that further optimization of system by the reduction of the core-size (from micron to nanometer-sized) would result in a monolayer (i.e.: a continuous shell) rather than discrete particles. Formation of a single layer of PGM (oxide) on the surface of the core material is reasonably expected to improve the electrical conductivity between the catalyst surface and the core material as well as providing the most efficient use of the catalyst. Both of these effects improve the efficiency of the IrOx OER catalyst.
Therefore, it would be obvious to one of ordinary skill in the art prior to the effective filings date of the claimed invention to reduce the particle size of the core disclosed by Scott et al. as suggested by Gong et al. while keeping the IrOx loading constant with the reasonable expectation of forming a continuous catalyst shell of iridium oxide on the core meaning the electrical conductivity of the core-shell material approaches pure IrO2
Secondly, Claim 1 claims the sequential steps of drying the coated inorganic core (i.e.: PGM precursor + inorganic core) and then combining with the template (e.g. alkali nitrate) followed by heating to form the PGM-oxide shell. On the other hand, Scott et al. discloses the drying step after the addition of the inorganic template (e.g.: NaNO3) followed by heating to form the IrO2 shell. Although the order of drying and adding the template are swapped, a prima facie case of obviousness exists regarding the selection in the order of performing these process steps. The steps of adding the inorganic template (i.e.: NaNO3) prior to drying is advantageous because it would result in a more efficient salt metathesis as per equation (2) and equation (3) of Scott et al. (pg. 452) since solid-liquid interfaces (as taught in Scott et al.) undergo more efficient chemical reactions than solid-solid interfaces (as per Claim 1). The solid-liquid interface occurs between the dissolved Ir-precursor and the solid sodium nitrate in contrast to the solid-solid interface between the solid Ir-precursor and solid sodium nitrate of the instant application. See MPEP 2144.04(IV): Rationale C – CHANGES IN THE SEQUENCE OF ADDING INGREDIENTS.
Regarding Claim 3, Scott et al. in view of Gong et al. disclose the method of Claim 1, wherein the inorganic template comprises NaNO3 as specified on pg. 452: 2.1. Catalyst Preparation section (of Scott et al).
Regarding Claim 6, Scott et al. in view of Gong et al. disclose the method of Claim 1, wherein the PGM comprises iridium as evidenced by pg. 451: abstract and pg. 452: 2.1. Catalyst Preparation section (of Scott et al.).
Regarding Claim 7, Scott et al. in view of Gong et al. disclose the method of Claim 1. Scott et al. teaches inventive examples that use ATO as the inorganic core (pg. 452: 2.1. Catalyst Preparation section of Scott et al.); however, Scott further indicates that the inorganic core is capable of being nanoparticulate TiO2 (pg. 456: 3.3. Powder conductivity section) in the comparative example.
Regarding Claim 8 and Claim 9, Scott et al. in view of Gong et al. disclose the method of Claim 1 wherein the water electrolysis catalyst comprises a catalyst loading ranging from 20 wt.% IrO2 on ATO to 90 wt.% IrO2 on ATO in the inventive examples (Scott et al. on pg. 454: Table 1 and pg. 455: Table 2 and Fig. 4). It has been held that a prima facie case of obviousness exists when the claimed ranges contains an example disclosed in the prior art. See MPEP 2144.05(I) - OVERLAPPING, APPROACHING, AND SIMILAR RANGES, AMOUNTS, AND PROPORTIONS.
6. Claim 19 is rejected under 35 U.S.C. 103 as being unpatentable over Scott et al. in view of Gong et al. as applied to Claim 1 and further in view of Baik et al.
Scott et al. (“Physical and Electrochemical Evaluation of ATO supported IrO2 Catalyst for Proton Exchange Membrane Water Electrolyzer,” J. Power Sources 2014, 269, 451-460) is directed toward an IrO2 catalyst shell on a ATO core (pg. 451: abstract). Gong et al. (“Recent Advances in Earth-Abundant Core/Noble-Metal Shell Nanoparticles for Electrocatalysis,” ACS Catal. 2020, 10, 10886-10904) is directed toward optimization of core-shell electrocatalysts (pg. 10886: abstract). Baik et al. (“Glycine-induced ultrahigh-surface-area IrO2@IrOx catalyst with balanced activity and stability for efficient water splitting,” Electrochimica Acta 2021, 390, article 138885, pg. 1-10) is directed toward a modified Adams fusion method of synthesizing iridium oxide (pg. 1: title and abstract).
Regarding Claim 19, Scott et al. and Gong et al. discloses the method of Claim 1, but only discloses the use of an inorganic template.
Baik et al. is directed toward a modified Adams fusion method of synthesizing iridium oxide (pg. 1: title and abstract) meaning it is analogous art to Scott et al. in view of Gong et al. The modification to the Adams fusion method is achieved by both the use of an inorganic template and a chelating agent (analogous to the organic template of the instant application). In particular, Baik et al. discloses the use of glycine and citric acid as the organic template indicating that these two species form a carbonized shell during the initial heating steps of the fusion despite slight differences in elemental composition (pg. 4: Scheme 1 and pg. 3-4: 3.1. Synthesis and characterization of OER catalysts). The carbonized shell decomposes at higher temperatures to form CO2. Baik et al. further indicated that the chelator/organic template (e.g.: glycine or citric acid) could be added in solution (i.e.: prior to the drying) or after the drying (prior to calcination) resulting in the same highly active IrO2 catalyst (pg. 3: 3.1. Synthesis and characterization of OER catalysts). Electrochemical comparison between A-450 (i.e.: control) and G-450 (i.e.: addition of organic template) indicated that the G-450 sample is a more active catalyst with higher specific surface area (pg. 6: Fig. 2d) having better electrochemical performance than the control A-450 as illustrated by Fig. 4a, Fig. 4b, Fig. 5a and Fig. 5b of Baik et al.
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 of Scott et al. and Gong et al. by incorporation of an organic template such as citric acid as taught by Baik et al. with the reasonable expectation of increasing the electrochemical OER performance of the resultant supported IrO2 catalyst. Therefore, the combination of Scott et al., Gong et al., and Baik et al. teach the use citric acid as an organic template as required by Claim 19.
Response to Arguments
7. Applicant’s arguments with respect to Claims 1, 3, 6, 7, 8, and 9 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument. The updated grounds for the rejection are explained above in detail and were required based on the applicant’s amendment to Claim 1 which removed the requirement that the inorganic core is electrically non-conductive. Moreover, the requirement for the template being inorganic was also withdrawn. Consequently, the search was expanded to include electrically conductive cores which are expected to have better catalytic activity than non-conductive cores.
8. New grounds for the rejection of Claim 19 (depending from Claim 1) based on the use of an organic template and an inorganic template are explained in detail above.
Conclusion
9. 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.
10. 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.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, James Lin can be reached at 571-272-8902. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
11. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/KEVIN SYLVESTER/Examiner, Art Unit 1794
/CIEL P CONTRERAS/Primary Examiner, Art Unit 1794
Prosecution Insights