Prosecution Insights
Last updated: April 19, 2026
Application No. 18/278,798

METHOD FOR PRODUCING HYDROGEN GAS, METHOD FOR STOPPING OPERATION OF APPARATUS FOR PRODUCING HYDROGEN GAS, AND HYDROGEN GAS PRODUCTION APPARATUS

Non-Final OA §103§112
Filed
Aug 24, 2023
Examiner
COHEN, BRIAN W
Art Unit
1759
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Mitsui Mining & Smelting Co. Ltd.
OA Round
1 (Non-Final)
54%
Grant Probability
Moderate
1-2
OA Rounds
3y 1m
To Grant
99%
With Interview

Examiner Intelligence

Grants 54% of resolved cases
54%
Career Allow Rate
343 granted / 633 resolved
-10.8% vs TC avg
Strong +47% interview lift
Without
With
+46.9%
Interview Lift
resolved cases with interview
Typical timeline
3y 1m
Avg Prosecution
28 currently pending
Career history
661
Total Applications
across all art units

Statute-Specific Performance

§101
0.3%
-39.7% vs TC avg
§103
53.7%
+13.7% vs TC avg
§102
17.5%
-22.5% vs TC avg
§112
22.0%
-18.0% vs TC avg
Black line = Tech Center average estimate • Based on career data from 633 resolved cases

Office Action

§103 §112
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. 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 appl icant regards as his invention. Claims 9-10 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 9 recites the limitation "the oxygen generating electrode." There is insufficient antecedent basis for this limitation in the claim. It is noted that the oxygen generating electrode is introduced in claim 8. Thus it is assumed that claim 9 should be dependent on claim 8 (not claim 7 as currently provided). Claim 10 is rejected as being dependent on claim 9. 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. 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 . Claim s 1- 8 and 11 are rejected under 35 U.S.C. 103 as being unpatentable over US 2020/0263310 of Ua Cearnaigh . As to claims 1 and 6, Cearnaigh teaches of a method for producing (and controlling) a hydrogen gas generating process ( Cearnaigh , [0050] and [0028] and [0071], [0074] ), the method comprising: operating a system in one or more production states at different potentials (thus decreased potentials and current density relative to the maxim um production potential) such that electrolysis occurs for different desired products or ratio of products ( Cearnaigh , [0059], [0062] – [0066] and Fig. 3 ); and decreasing the potential from the production state to a non-zero potential (idle state) in which the electrolysis does not take place while introducing an inert gas to at least a hydrogen generating electrode ( Cearnaigh , [0068] – [0078], [0082] ). As stated within Cearnaigh , an electrolytic system that produced hydrogen gas performs some version of being in an operating state. The operating state can include multiple potentials at which products are formed (see Fig. 3, points, 324, 326, 328, 332) such that the system has some applied potential which has some generated current (and thus current density in relation to the area of the electrode). After some production time, the system is put into an idle mode such that a non-zero potential (and thus non-zero current) is applied to maintain the system in a non-production mode which allows for a minimal potential to be applied to the system such that damage to the cell does not occur to the system in a non-producing state. Although Cearnaigh does not specifically state the process of holding the decreased potential for 1 second or more while introduce a gas, this would be obvious in view of Cearnaigh . Cearnaigh teaches that in going from a production state to the idle state, gas is simultaneously provided to the cell (both electrode sides) while the voltage is dropped over the course of time (18 second minimum or in a matter of minutes) so that the electrodes are protected from degradation ( Cearnaigh , [0068] and [0072] ). Therefore it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention as per Cearnaigh to stepwise decrease the potential, and thus the current, applied to the system while introducing a gas to the electrodes in order to protect the electrodes from degradation when going from a production to idle state for the system. As to claims 2 and 3, Cearnaigh teaches the gas is nitrogen or an inert (i.e. noble) gas ( Cearnaigh , [0072] ). As to claim 4, Cearnaigh teaches prior to the electrolysis being stopped, the potential (and thus current density) is decreased to a minimum potential for activation or over potential, thus the system being optimized while maintaining protection against a reverse current ( Cearnaigh , [0059] and [006 9 ] ). As to claim 5, Cearnaigh teaches that ramping from a production state to an idle state can take 5 minutes, thus a potential (and current density thereof) being applied for more than 30 seconds ( Cearnaigh , [0068] ). As to claim 7, Cearnaigh teaches a memory or storage media to store the method of the claim; and a controller ( Cearnaigh , [0144] and [0145] ). As to claim 8, Cearnaigh teaches the system comprises: two electrodes and a membrane separating the electrodes such that the membrane is a solid polymer membrane ( Cearnaigh , [0060], [0075] and Fig. 4A ). As to the limitation that the electrode is an oxygen generating electrode, this is the use of the electrode. As there is an anode and cathode within the system, one can be an oxygen generating electrode and one can be a hydrogen generating electrode. As to claim 11, Cearnaigh teaches of the system of claim 7. Cearnaigh teaches of a controller to control the potentials of the electrodes ( Cearnaigh , [0144] – [0145] ). As the anode is the oxygen/chlorine generating electrode and the cathode is the hydrogen generating electrode, Cearnaigh , in its normal operation would maintain the anode at a higher (more positive) potential than the cathode . Claim 9 is rejected under 35 U.S.C. 103 as being unpatentable over Ua Cearnaigh as applied to claim 8 above, and further in view of US 10,472,726 of Arai et al . As to claim 9, Cearnaigh teaches to the system of claim 8. Cearnaigh does not teach the specific composition of the electrodes. Arai teaches to electrolysis system and prevention of a reverse current in systems including electrolytic systems for chlorine and hydrogen generation ( Arai, col 1 thru col 2 ). Arai additionally teaches that the electrodes (anode and a cathode) comprise platinum to produce the desired gases ( Arai, col 11 lines 35-62 ). Therefore it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to modify Cearnaigh as per Arai so as to utilize the desired electrode compositions in order to provide a composition that would produce a predictable result in the desired gases formed during electrolysis. Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Cearnaigh in view of Arai or Cearnaigh as applied to claim 9 above, and further in view of US 2020/0316075 of Harada et al . As to claim 10, Cearnaigh in view of Arai teaches to the system of claim 9. Arai teaches that the electrodes comprise platinum, but not iridium. Harada teaches of water electrolysis systems ( Harada, [0003] ). Harada additionally teaches that the oxidation reaction generating electrode (i.e. anode) can comprise platinum or iridium as equivalent catalyst compositions ( Harada, [0022] ). As Arai teaches that at the anode, chlorine and oxygen can be formed ( Arai, col 1 lines 30-41 ), it would be obvious to one of ordinary skill in the art before the effective filing date of the claimed invention as per Harada to substitute iridium for platinum in producing a predictable result in the formation of a viable oxidation electrode. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to FILLIN "Examiner name" \* MERGEFORMAT BRIAN W COHEN whose telephone number is FILLIN "Phone number" \* MERGEFORMAT (571)270-7961 . The examiner can normally be reached FILLIN "Work Schedule?" \* MERGEFORMAT M-F: 9 am to 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, FILLIN "SPE Name?" \* MERGEFORMAT Duane Smith can be reached at FILLIN "SPE Phone?" \* MERGEFORMAT 571-272-1166 . The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. 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. FILLIN "Examiner Stamp" \* MERGEFORMAT BRIAN W. COHEN Primary Examiner Art Unit 1759 /BRIAN W COHEN/ Primary Examiner, Art Unit 1759
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Prosecution Timeline

Aug 24, 2023
Application Filed
Mar 13, 2026
Non-Final Rejection — §103, §112 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
54%
Grant Probability
99%
With Interview (+46.9%)
3y 1m
Median Time to Grant
Low
PTA Risk
Based on 633 resolved cases by this examiner. Grant probability derived from career allow rate.

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