DETAILED ACTION
Application 18/184409, “CATALYST LAYER”, was filed with the USPTO on 3/15/23 and claims priority from a foreign application filed on 3/22/22.
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
This Office Action on the merits is in response to communication filed on 12/30/25.
Response to Arguments
Applicant’s arguments filed on 12/30/25 have been fully considered, but are moot in view of the new ground(s) of rejection necessitated by amendment.
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 of this title, 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.
Claims 1, 2, 4 and 5 is/are rejected under 35 U.S.C. 103 as being unpatentable over Tsukuda (US 2017/0279143).
Regarding claims 1-2, Tsukuda teaches a catalyst layer (paragraphs [0002, 0009]; Fig. 1 item 2; Fig. 4), comprising: an electrode catalyst (paragraph [0047]), and an ionomer (paragraph [0050]), wherein the catalyst electrode particles having a structure (connected structure) in which porous primary particles composed of an assembly of fine crystallites are connected to each other in a bead shape (see Fig. 4 which illustrates tin oxide particles comprising connected bead-like particles formed as an agglomeration of fine crystallites such that an internal porous structure is formed within the beads; the Examiner’s Modified Fig. 4 below delineates a plurality of individual beads pressed together to form the structure, each bead formed by smaller crystallites such that internal porous structure is present; see also paragraph [0046] which mentions 5-200 nm sized “primary particles” which are readable on the claimed crystallites while the larger particles [such as in Examiner’s Modified Fig. 4] are of a micron scale size; see also the description of “generally spherical” particles at paragraph [0082]) and Pt-based fine particles supported on the surface of the tin oxide-based particles (paragraph [0047]), wherein the catalyst particles art tin-oxide particles (paragraph [0045]). Tsukuda further teaches wherein the tin oxide-based particles include Sb, Nb, Ta, and/or W-doped SnO2 (paragraph [0045]).
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Tsukuda does not expressly teach that specific surface area of the tin-oxide particle support has a specific surface area of 30 m2/g or more.
However, Tsukuda does teach that it is preferred for the support to have a “high specific surface area” and gives a preferred range of 10 to 500 m2/g (paragraph [0046]).
The claimed range of 30 m2/g or more is found to be obvious because the Kakinuma range largely overlaps the claimed range, and Kakinuma further teaches that the high values are desirable.
Regarding claim 4, the cited art remains as applied to claim 1. Tsukuda further teaches wherein a conductivity of a green compact composed of the tin oxide-based particles is 1×10−3 S/cm or more (e.g. 1.31 ohm cm at Table 2 converts to 0.763 X 10-3 S/cm. The claimed range is found to be taught as 0.763 X 10-3 S/cm rounds to 1 X 10-3 S/cm with one significant digit).
Alternatively, the 1×10−3 S/cm or more range is found to be obvious over Tsukuda because Tsukuda teaches the oxide of the support should have electron conductivity, such as a volume resistivity of 1 M[Symbol font/0x57]cm or less (paragraph [0045]) suggesting an overlapping range. Absent further limitation which enables the conductivity of 1×10−3 S/cm or more, the recitation is merely aspirational as there is no upper limit on the conductivity and there is not specific claimed structure that enables achievement of the high conductivity value. Since Tsukuda teaches the same aspiration, the limitation is found to be obvious.
Regarding claim 5, the cited art remains as applied to claim 1. Tsukuda further does not expressly teach wherein an average particle diameter of the Pt-based fine particles is 5 nm or less.
However, Tsukuda does teach the particles having an average size of 1 to 10 nm (paragraph [0047]).
The claimed range is found to be obvious for overlapping the prior art range at least at 1-5 nm, which is a significant portion of the prior art range (See MPEP 2144.05 for more information on obviousness associated with overlapping ranges).
Claims 3 is/are rejected under 35 U.S.C. 103 as being unpatentable over the combination of Tsukuda (US 2017/0279143) and Watanabe (US 2012/0295184).
Regarding claim 3, the cited art remains as applied to claim 1. Tsukuda teaches that the tin-oxide based particle may be doped with Sb (see rejection of claim 2), but does not appear to teach wherein the tin oxide-based particles include Sb-doped SnO2, and a doping amount of Sb in the Sb-doped SnO2 is 2.5 at % or more and 15.0 at % or less.
In the fuel cell art, Watanabe teaches a catalyst support tin oxide, wherein the tin oxide is SnO2 is doped with four atomic percent Sb (“Sn0.96Sb0.04O2”, paragraph [0075]).
The replacement of the antimony doped tin-oxide of Tsukuda with the Sn0.96Sb0.04O2 taught by Watanabe merely requires the simple substitution of one known element for another to yield the predictable result of a functional catalyst system; therefore, a prima facie case of obviousness for substitution exists. The Watanabe Sn0.96Sb0.04O2 lies within the claimed Sb range, the claim 3 is obvious over the cited art.
Claim 6 is/are rejected under 35 U.S.C. 103 as being unpatentable over the combination of Tsukuda (US 2017/0279143) and Kitabatake (US 2023/0049734).
Regarding claim 6, Tsukuda remains as applied to claim 1. Tsukuda does not appear to teach wherein a ratio (=I/S) of a mass (I) of the ionomer to a mass (S) of the tin oxide-based particles is 0.13 or more and 0.39 or less.
In the fuel cell art, Kitabatake teaches that an electrode catalyst layer may be configured to include an ionomer for the benefit of improving performance of the catalyst layer, and that it is advantageous to adjust the amount of the ionomer and the amount of the catalyst/support composite, such that the I/M ratio is 0.07 or more and 0.25 or less, for the benefit of improving the performance of the electrode catalyst layer (paragraph [0033]).
It would have been obvious to a person having ordinary skill in the art at the time of invention to modify the catalyst layer of Tsukuda by including ionomer at an ionomer to catalyst/support ratio of is 0.07 to 0.25 for the benefit of improving the performance of the catalyst layer as taught by Kitabatake. The claimed range is found to be obvious since the presence of ionomer is suggested, with the ionomer to catalyst ratio being a result effective variable, and the prior art suggested range substantially overlaps the claimed range.
Claims 7 and 8 is/are rejected under 35 U.S.C. 103 as being unpatentable over the combination of Tsukuda (US 2017/0279143) and Edwards (US 2007/0031322).
Regarding claim 7 and 8, the cited art remains as applied to claim 1-3. The requirement that the specific surface area is 90 m2/g or more is found to be obvious for similar reasons as the 30 m2/g or more requirement of claim 1, namely that Tsukuda teaches a substantially overlapping range.
Tsukuda further teaches that catalyst layer may comprise pores of preferably 5 to 50 nm size (paragraph [0046]), but does not expressly teach the narrowed range wherein a pore diameter of the tin oxide-based particles is 5 nm or more and 8 nm or less.
In the fuel cell art, Edwards teaches that catalyst materials with a substantial number of small pores, such as less than 7 nm, tend to exhibit high surface area, which is useful in catalyst applications as the catalyst uses the surface area (paragraph [0019]).
It would have been obvious to a person having ordinary skill in the art at the time of invention to configure the primary particles to include pores having a diameter of less than 7 nm for the benefit of increasing the surface area for catalysis as taught by Edwards. The claimed range of 5 nm to 8 nm is found to be obvious over the cited art because the less than 7 nm range overlaps the claimed range at least at 5 to 7 nm, and differences in scale do not provide patentability absent a showing of functional criticality associated with the difference (MPEP 2144.04 IVA).
Claims 9 and 10 is/are rejected under 35 U.S.C. 103 as being unpatentable over the combination of Tsukuda (US 2017/0279143) and Steinback (US 2022/0059849).
Regarding claims 9 and 10, the cited art remains as applied to claim 1. Tsukuda further teaches that the catalysts of the invention provide “improved power output and small humidity dependence of power output” (paragraph [0008]), implying favorable behavior under both low and high humidity conditions, but is silent as to the mass activity under the conditions described in claims 9 and 10.
Additionally, in the fuel cell art, Steinback teaches: “PEMFC electrocatalysts often comprise platinum, a relatively expensive precious metal. It is typically desirable to minimize the platinum content in PEMFC devices to minimize cost. Sufficient platinum content, however, is needed to provide sufficient catalytic activity and PEMFC device performance. As such, there is a desire to increase the catalyst activity per unit catalyst mass (mass activity). There are two general approaches to increase the mass activity, namely increasing the catalyst activity per unit catalyst surface area (specific activity) and increasing the catalyst surface area per catalyst mass (specific surface area or specific area). The HOR and ORR occur on the catalyst surface, so increasing the specific surface area and/or the specific activity can reduce the amount of catalyst needed to achieve a desired absolute performance, reducing cost” at paragraph [0002].
The claimed invention is found to be unpatentable over the cited art because either i) the catalyst layer of tsukuda (in view of the secondary references applied in the rejection of claim 1 would possess the claimed mass activity if measured under the same conditions due to the structural similarity previously set forth and the disclosure of output independence on humidity, or ii) it would have been obvious to increase the mass activity in order to minimize the amount of platinum required in the catalyst layer, with Steinback expressly teaching it desirable to reduce platinum content and suggesting techniques for increasing mass activity. It is noted that claims 9 and 10 merely set forth ranges expressing high mass activity without adding additional structure beyond that recited in claim 1 which facilitates achievement of the high mass activity which is claimed.
Claims 11 is/are rejected under 35 U.S.C. 103 as being unpatentable over the combination of Tsukuda (US 2017/0279143) and Easton (US 2021/0351415).
Regarding claims 11, the cited art remains as applied to claim 1. Tsukuda is silent as to the ECSA reduction ratio measured under the conditions described in claim 11.
However, in the fuel cell art, Easton teaches that a known problem in PEM fuel cells is lack of durability due to decrease in surface area (ECSA) of supported catalysts, particularly when the support is a carbon material, and the use of metal oxide is adopted in order to mitigate this deterioration (paragraph [0003]), indicating that enhanced durability of ECSA is associated with the selection of a particular catalyst support material. Easton further teaches inventive embodiments wherein the electrocatalyst exhibits only slight decay over thousands of cycles, significantly outperforming carbon supported catalysts (paragraphs [0107-0114]).
The claimed invention is found to be unpatentable over the cited art because either i) the catalyst layer of Tsukuda (in view of the secondary references applied in the rejection of claim 1 would possess the claimed ECSA reduction ratio if measured under the same conditions due to the structural similarity previously set forth, or ii) it would have been obvious to decrease the ECSA reduction ratio to the claimed amount through routine experimentation designed to achieve the known goal of minimizing the surface area loss as taught by Easton. It is noted that claim 11 merely set forth an achievement in terms of ECSA reduction without adding additional structure, elements, or features beyond that recited in claim 1 which facilitates achievement of the claimed property.
Double Patenting
The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969).
A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159. See MPEP § 2146 et seq. for applications not subject to examination under the first inventor to file provisions of the AIA . A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b).
The filing of a terminal disclaimer by itself is not a complete reply to a nonstatutory double patenting (NSDP) rejection. A complete reply requires that the terminal disclaimer be accompanied by a reply requesting reconsideration of the prior Office action. Even where the NSDP rejection is provisional the reply must be complete. See MPEP § 804, subsection I.B.1. For a reply to a non-final Office action, see 37 CFR 1.111(a). For a reply to final Office action, see 37 CFR 1.113(c). A request for reconsideration while not provided for in 37 CFR 1.113(c) may be filed after final for consideration. See MPEP §§ 706.07(e) and 714.13.
The USPTO Internet website contains terminal disclaimer forms which may be used. Please visit www.uspto.gov/patent/patents-forms. The actual filing date of the application in which the form is filed determines what form (e.g., PTO/SB/25, PTO/SB/26, PTO/AIA /25, or PTO/AIA /26) should be used. A web-based eTerminal Disclaimer may be filled out completely online using web-screens. An eTerminal Disclaimer that meets all requirements is auto-processed and approved immediately upon submission. For more information about eTerminal Disclaimers, refer to www.uspto.gov/patents/apply/applying-online/eterminal-disclaimer.
Claims 1, 2, 4, 5 and 12 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-9 of U.S. Patent No. 12,304,830 (Inaba herein) in view of Tsukuda (US 2017/0279143).
Regarding claims 1, 2, 4, 5, and 12, Inaba claims a porous oxide (claims 1), which may have a structure in which primary particles composed of fine crystallites are connected to each other in a connected structure (claim 1). Inaba further claims that the porous oxide may be SnO2 or a doped variant thereof (claim 7). Inaba further claims that the porous oxide may be used as a catalyst support for a fuel cell (claim 9). Inaba further claims similar properties such as particle sizes and material properties as does the instant invention (see Inaba claims).
As to instant claim 12, Inaba does not claim the method recited in the product-by-process limitations; however, the patentability of a product-by-process claim is determined by the structure implied by recited process steps. Here, the available evidence suggests that the claimed process produces a structure which is substantially the same as that claimed in Inaba claim 1. See for example Inaba’s description which indicates that the claimed product is made by a process using a carbon porous body template, similar to applicant’s product-by-process limitations. It is noted that the description of Inaba is only relied on to interpret the Inaba claims and assist in evaluating whether the structure implied by the process limitations of instant claim 12 is the same or obvious over the product claimed by Inaba. Since the structure implied by present claim 12 is obvious over that positively claimed in Inaba claim 1, the presently claimed invention is found to be obvious over Inaba.
It is noted that although Inaba claims a porous oxide to be used as a catalyst support of a polymer electrolyte fuel cell (claim 9), Inaba does not clarify the structure of of such a fuel cell or explain how the catalyst support should be used.
However, at least in view of Tsukuda, a skilled artisan would have understood that the porous oxide may be included in a catalyst layer comprising the porous oxide of Inaba as a support, catalyst fine particles supported on the support, and an ionomer, for the benefit of making functional use of the catalyst support.
It would have been obvious to a person having ordinary skill in the art at the time of invention to employ the porous oxide particles of Inaba in a catalyst layer as presently claimed, in order to make use of the porous catalyst.
It is further noted that the catalyst layer of the present claims and the porous oxide of Inaba are related as a combination-subcombination. However, the indicated patentability of the catalyst layer is determined by considering the implied structure of the tin-oxide particles (see indication of allowable subject matter below), which is the same as the patentable subject matter of Inaba. Therefore, the inventions are not considered distinct (see MPEP 806.05 C).
Claims 3, 6-11 are rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-9 of U.S. Patent No. 12,304,830 (Inaba herein) in view of Tsukuda (US 2017/0279143), and further in view of Watanabe (US 2012/0295184), Kitabatake (US 2023/0049734), Edwards (US 2007/0031322) Steinback (US 2022/0059849), or Easton (US 2021/0351415).
Regarding claims 3 and 6-11, Inaba and Tsukuda remain as applied to claim 1. The deficiencies of Inaba’s claims with respect to claims 3 and 6-11 are found to be obvious over the cited secondary references for the same reasons, mutatis mutandis, as detailed in the art rejections.
Allowable Subject Matter
Claim 12 is objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims, and the obviousness-type double patenting rejection were overcome.
The following is an examiner’s statement of reasons for allowance:
Regarding dependent claim 12, the closest prior art includes Tsukuda (US 2017/0279143), which is applied in the art rejections herein, and Kakinuma (US 2017/0250409), which was applied in the art rejections of the 10/1/25 Non-Final Rejection.
As described herein, Tsukuda teaches a catalyst layer comprising tin-oxide particles having a connected structure in which porous primary particles composed of an assembly of fine crystallites are connected to each other in a bead shape. However, the Inaba NPL filed on 12/30/25, by an inventor of the present invention, suggests that the method recited in claim 12 produces a particular structure which is different from that of Tsukuda (see the Inaba NPL and the disclosure of Tsukuda). Moreover, Kakinuma has been previously applied for teaching a catalyst layer comprising a bead structure, but the structure is not made by the method recited in claim 12 and omits the fine crystallites of claim 1. Therefore, the invention of claim 12 is found to be nonobvious over the disclosures of Tsukuda and Kakinuma.
A diligent search has been performed, but has not yielded a closer prior art which can cure the deficiency of Tsukuda or Kakainuma, or which can independently teach the invention of claim 12, including all the positively recited structural limitations of base claim 1. Therefore, claim 12 is not rejected, but is objected to for being dependent on a rejected base claim 1.
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.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JEREMIAH R SMITH whose telephone number is (571)270-7005. The examiner can normally be reached Mon-Fri: 9 AM-5 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, Tiffany Legette-Thompson can be reached on (571)270-7078. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/JEREMIAH R SMITH/Primary Examiner, Art Unit 1723
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