CATALYST FOR FUEL CELL AND METHOD FOR PREPARING THE SAME
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 .
Election/Restrictions
Applicant’s election without traverse of Species II, claims 6-14 in the reply filed on 12/4/2025 is acknowledged.
Priority
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Information Disclosure Statement
The information disclosure statements (IDS) submitted on 2/22/2024 and 8/15/2025 are in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statements are being considered by the examiner.
Claim Objections
Claim 6 objected to because of the following informalities: for consistency, please amend to 200 m2/g to about 500m2/g. Appropriate correction is required.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 6-14 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 6 discloses the specific surface area of the crystalline carbon support twice in the claim. There is no explanation or reason for why this occurs in the specification.
Claims 7-14 are also rejected under 35 USC 112(b) for their dependence on claim 6.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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.
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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 6 and 10 are rejected under 35 U.S.C. 103 as being unpatentable over Jang et al., (Sci. Rep., 3, 2872, (2013)), and further in view of Kuttiyiel et al. (Nano Energy, 13, 442-449, (2015)), Terazono et al. (US 2009/0162725 A1) and Takahashi et al. (US 2016/0233520 A1) and Tanaka et al. (US 2012/0046164 A1) and Haug et al. (WO 2014/105407 A1).
Regarding claim 6, Jang et al. teach a method of preparing a catalyst for a fuel cell (Abstract), the method comprising: irradiating ultrasonic waves to a precursor mixed solution including a noble metal precursor, a transition metal precursor, and a crystalline carbon support (Page 7, Sample preparation discloses a dispersion of Pt(acac)2, Fe(acac)3, with Ketjen Black was irradiated with ultrasound by a high-intensity ultrasonic probe.); intermetallic active particles of a transition metal and a noble metal (Abstract discloses iron and platinum, a transition metal and a noble metal, respectively.), wherein the intermetallic active particles are supported on the crystalline carbon support and have a particle diameter of greater than or equal to about 3 nm (Page 5, left column, first paragraph discloses 4 nm in diameter.), and wherein the noble metal comprises platinum (Pt) and the transition metal comprises iron (Fe) (Abstract).
However, Jang et al. do not teach annealing the core-shell particles and forming intermetallic particles including a transition metal oxide coating layer; and removing the transition metal oxide coating layer from the intermetallic particles.
Kuttiyiel et al. teach synthesizing fuel cell catalyst comprising transition metal nitride cores (Introduction, third paragraph discloses Fe or Fe nitride cores) with platinum metal shells on carbon supports (Abstract). The synthesis involves using K2PtCl4 (51.9 mg) and FeCl6·6H2O (115.4 mg) salts mixed with high-area Vulcan XC72R carbon black (105.8 mg). The dried powder was annealed at 510 °C under NH3 gas for 2 h in a tube furnace. Then the sample was then washed in 0.1 M H2SO4 to dissolve Fe precipitates on the carbon support surface, and rinsed and dried again (Experimental: Material synthesis). While forming a transition metal oxide coating layer during annealing is not specifically disclosed in Kuttiyiel, the final step of the synthesis involves an acid washing step to “dissolve Fe precipitates” formed. These precipitates would understandably to one of ordinary skill in the art comprise iron oxides being that iron easily hydrolyzes in an aqueous medium (0.1M 0.1 M H2SO4 is a very dilute acid concentration). The iron oxides would clearly comprise, depending on the iron oxidation state(s), various oxides such as Fe2O3 and/or Fe3O4.
Therefore, it would have been obvious to one of ordinary skill in the art to modify Jang with Kuttiyiel in order to reduce Pt loading while increasing ORR activity.
However, neither Jang nor Kuttiyiel teach a crystalline carbon support having a specific surface area of about 200 m2/g to about 500 m2/gm, and forming core-shell particles including a transition metal oxide coating layer; and wherein the catalyst comprises a crystalline carbon support having a specific surface area of about 200 m2/g to about 500 m2/g.
Terazono et al. teach an electrode for a fuel cell comprising a platinum or platinum alloy support on carbon (Abstract). Further the platinum alloy can comprise platinum, cobalt, and zinc (Paragraph 0027) and the carbon support can comprise carbon black having a surface area from 100-1000 m2/g (Paragraph 0047).
Therefore, it would have been obvious to one of ordinary skill in the art to modify Jang and Kuttiyiel with Terazono in order to suppress the formation of flooding due to hydrophobic carbon support.
However, Jang, Kuttiyiel, and Terazono do not teach wherein the catalyst comprises more than about 0% and about 40% or less by number of the intermetallic active particles embedded in pores of the carbon support, and more than about 60% and about 100% or less by number of the intermetallic active particles present in a surface of the carbon support with respect to a total number of the intermetallic active particles.
Takahashi et al. teach a carbon powder for a catalyst metal supported on said carbon powder (Claims 1 and 3). The catalyst can comprise platinum or alloys thereof (Paragraph 0080-0081). Further, Takahashi et al. disclose a catalyst 20 is composed of catalyst metal 22 and catalyst support (carbon powder of the present invention) 23. The catalyst 20 includes pores (micropores) 25 having a radius of less than 1 nm and pores (mesopores) 24 having a radius of 1 nm or more. The catalyst metal 22 is supported inside the mesopore 24. In addition, at least a portion of the catalyst metals 22 may be supported inside the mesopores 24, and at least a portion thereof may be supported on the surface of the catalyst support 23. However, in view of preventing the catalyst metal from being contacted with an electrolyte in a catalyst layer, it is preferable that substantially all the catalyst metals 22 be supported inside the mesopores 24. As used herein, the expression “substantially all the catalyst metals” is not particularly limited if an amount which can improve a sufficient catalytic activity can be attained. The amount of “substantially all the catalyst metals” is preferably 50 wt % or more. (See figure 2 and paragraph 0098).
While Takahashi do not explicitly state the catalyst is more than about 0% and about 40% or less by number in the pores of the carbon support and more than about 60% and about 100% or less of the intermetallic active particles present in a surface of the carbon support, Takahashi can at best disclose 50% in the pores of the carbon and 50% on the surface. Therefore, this is merely an example of routine optimization.
MPEP 2144.05 II. ROUTINE OPTIMIZATION
A. Optimization Within Prior Art Conditions or Through Routine Experimentation
Generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955).
Therefore, it would have been obvious to one of ordinary skill in the art to modify Jang, Kuttiyiel, and Terazono with Takahashi in order to improve catalytic action.
However, Jang, Kuttiyiel, Terazono, and Takahashi do not teach wherein the intermetallic active particles comprise an intermetallic core of a transition metal and a noble metal, and a noble metal skin layer surrounding the intermetallic core.
Tanaka et al. disclose catalyst materials such as Pt alloys in a core-shell structure for use in a fuel cell (Paragraphs 0062-0064). Further, Tanaka discloses one way to improve the catalytic activity is by increasing the number of platinum atoms contributing to the catalytic activity among the total platinum atoms used to form the catalyst electrode layer. The number of platinum atoms contributing to the catalytic activity means the number of platinum atoms exposing themselves on the surface of the catalyst particles. For improvement in catalytic activity, it is necessary to increase the surface density of platinum atoms forming the surface of catalyst particles (Paragraph 0036). Tanaka et al. also disclose the core can comprise noble metals along with transition metals such as Fe (Claim 7) and a shell (or skin) comprising only noble metals such as Pt (Claim 8). When the catalyst is measured for catalytic activity, the materials with a Pt skin show a higher output retention than a Pt-M alloy which, to one of ordinary skill in the art, implies that most, if not all, of the catalyst is participating in catalytic activity (Paragraph 0158).
Therefore, it would have been obvious to one of ordinary skill in the art to modify Jang, Kuttiyiel, Terazono, and Takahashi with Tanaka in order to improve durability, output density, and output retention.
However, Jang, Kuttiyiel, Terazono, Takahashi, and Tanaka do not teach wherein the crystalline carbon support has a carbon shell thickness of about 3 nm to about 6 nm.
Haug et al. teach an electrode for a fuel cell comprising a Pt-Co alloy (Abstract). Further, the catalyst is supported on a carbon support which can have a thickness in a range of 5-100 nm (Paragraph 0002).
Therefore, it would have been obvious to one of ordinary skill in the art to modify Jang, Kuttiyiel, Terazono, Takahashi, and Tanaka with Haug in order to improve the limiting current.
Regarding claim 10, the combination of Jang, Kuttiyiel, Terazono, Takahashi, Tanaka, and Haug et al. teach the method of claim 6. Further, Takahashi et al. teach wherein annealing is performed at about 700 °C to about 1200 °C for about 2 hours to about 4 hours (Paragraph 0112 discloses heat treatment occurs at a range of 300 to 1200° C., more preferably in the range of 500 to 1150° C., particularly preferably in the range of 700 to 1000° C. A heat treatment time is preferably in the range of 0.02 to 3 hours, more preferably in the range of 0.1 to 2 hours.).
Therefore, it would have been obvious to one of ordinary skill in the art to modify Jang, Kuttiyiel, and Terazono with Takahashi in order to improve catalytic action.
Allowable Subject Matter
Claims 7-9 and 11-14 would be allowable if rewritten to overcome the rejection(s) under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), 2nd paragraph, set forth in this Office action and to include all of the limitations of the base claim and any intervening claims.
The following is a statement of reasons for the indication of allowable subject matter: the subject matter of claims 7-9 and 11-14 are not disclosed in the subject matter. While Kuttiyiel teach the formation of a metal oxide layer during the annealing process, which is removed, there is no indication of surround the platinum shell or group of particles as required by claims 7 and 9. While Jang et al. disclose irradiation of ultrasonic waves, they do not disclose the time and power settings of the step as required by claim 8. Takahashi discloses the annealing step but only discloses an inert gas like N2 or Ar are used in the step, not a mixture also comprising hydrogen which is required by claim 11. Finally, while Kuttiyiel does disclose an acid treating step using sulfuric acid, as required in claim 13, at a concentration of 0.1M. as required by claim 14, they are dependent on claim 12 which is indicated as having allowable subject matter. For claim 12, Kuttiyiel does not disclose the time and temperature for the acid treatment step.
Conclusion
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Daniel S. Gatewood, Ph.D.
Primary Examiner
Art Unit 1729
/DANIEL S GATEWOOD, Ph. D/Primary Examiner, Art Unit 1729 December 17th, 2025
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