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 .
Response to Arguments
Applicant’s amendment to claim 11 is clearly sufficient to overcome the rejection under 35 U.S.C. 112(b) for claims 11-14 set forth in the prior Office action.
Applicant’s amendment to claim 15 is sufficient to overcome the anticipation rejection of claims 15-17 and 20-21 in view of Porta et al.
Applicant's arguments filed 28 July 2026 have been fully considered but they are not persuasive. Applicant has argued that White et al do not teach flowing the two-phase solution “over and through” at least a portion of an electrode.
In response, the claims must be examined using their broadest reasonable interpretation. Here, “flowing the two-phase solution over and through at least a portion of an electrode” is much broader than the flow pattern seen in the figures of the specification. Further, since “over and through” does not recite a particular direction and also is only with respect to “at least a portion of an electrode”, flow of the solution of White et al from the surface of the electrode opposite to the membrane to the surface of the electrode in contact with the membrane is flow “through at a least a portion of an electrode”. White et al clearly teaches the flow “over … at least a portion of an electrode” (as noted by Applicant’s arguments, see White et al at col. 4, lines 24-31). Thus, White et al teach flowing the two-phase solution over and through at least a portion of an electrode, as claimed.
Note that for similar reasons amended claim 15 is newly rejected using White et al as the primary reference. However, this new ground of rejection is necessitated by Applicant’s additions to claim 15.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claims 1, 2, 5, 6, and 10 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by White et al (US 5,645,700 A), with evidence from Liu et al (“Morphological Properties and Electrochemical Performance for Compressed Carbon-fiber Electrodes in Redox Flow Batteries”).
White et al teach (see abstract, fig. 1, col. 5, line 55 to col. 6, line 13 and col. 7, lines 1-20) a method comprising mixing a liquid (11) and a gas (13) to form a two-phase solution; flowing the two-phase solution over an electrode (cathode 4, including catalyst layer 5 and current collector/electrically conductive material 9) comprising a substrate (current collector/electrically conductive material 9) made from carbon paper; and applying a voltage to the electrode wherein at least a portion of the gas participated in a reaction to electrochemically generate a compound at the electrode.
Note that White et al do not teach that the carbon paper included non-woven fibers.
Liu et al is cited as evidence showing the structure of carbon materials referred to as carbon cloth, carbon paper, and carbon felt. See Fig. 2 and Table 1. Carbon paper is a non-woven carbon material.
Thus, the evidence of record shows that the carbon paper material of White et al inherently included non-woven carbon fibers.
The direct teachings of White et al show that the two-phase solution was flowed over the electrode. However, at least some of the two-phase solution would have been expected by one of ordinary skill in the art to have also flowed through at least a portion of the electrode. The catalyst of White et al was only located on the surface of the carbon paper that was adjacent to the membrane, and thus for the solution to react at the catalyst, it inherently must have passed through at least a portion of the electrode in the thickness direction.
Regarding claim 2, the cathode of White et al included a catalyst layer (5) on the substrate.
Regarding claim 5, White et al teach the method producing hydrogen peroxide (abstract).
Regarding claim 6, White et al teach the gas was oxygen (abstract).
Regarding claim 10, White et al teach the electrode being the cathode (fig. 1, col. 5, lines 58-60).
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.
Claims 3, 4, 8, 9, and 28 are rejected under 35 U.S.C. 103 as being unpatentable over White et al (US 5,645,700 A).
Regarding claims 3 and 4, it would have been within the ordinary level of skill in the art to have performed routine experimentation to determine workable ranges for the flow rate of the liquid and the gas in order to achieve the desired production of hydrogen peroxide within the method of White et al. Additionally, the size of the electrochemical cell, absent a showing of criticality is considered to be prima facie obvious. See MPEP 2144.04.IV.A.
Regarding claims 8 and 9, it would have been within the ordinary level of skill in the art to have performed routine experimentation to determine workable ranges for the flow rate of the liquid and the gas in order to achieve the desired production of hydrogen peroxide within the method of White et al.
Regarding claim 28, White et al fail to teach the thickness (i.e. the smallest dimension) of the carbon paper being in the range of 1-5 mm. However, absent a showing of unexpected results, it would have been within the ordinary level of skill in the art to have conducted routine experimentation to determine a suitable thickness of carbon paper for providing sufficient current collection and surface area.
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over White et al (US 5,645,700 A) as applied to claim 1 above, and further in view of Carles et al (FR 2493878 A1).
White et al teach the liquid being water, thus failing to teach the liquid also including an alkali hydroxide. Note that White et al desired to produce a neutral hydrogen peroxide solution.
In the same electrolytic production of hydrogen peroxide field, Carles et al teach that sometimes it was desirable to produce an alkaline (pH>7) hydrogen peroxide solution and that having an alkali metal hydroxide dissolved in the liquid in combination with oxygen gas exposure at the cathode resulted in production of an alkaline hydrogen peroxide solution.
Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have modified the method of White et al according to the suggestion of Carles et al to produce an alkaline hydrogen peroxide solution instead of a neutral hydrogen peroxide solution when needed by adding an alkali metal hydroxide to the liquid.
Claims 11-14 are rejected under 35 U.S.C. 103 as being unpatentable over White et al (US 5,645,700 A) as applied to claim 1 above, and further in view of Gopal (US 2003/0019758 A1).
White et al teach the catalyst layer being formed on a portion of the non-woven substrate (col. 6, lines 45-60 and col. 7, lines 1-10).
White et al fail to teach the electrode including a hydrophobic polymer, the catalyst layer comprising a hydrophobic polymer or the active material comprising carbon.
Gopal teaches (see abstract, fig. 1, paragraphs [0041]-[0042]) alternative cathode electrode designs for an electrolytic cell used for production of a hydrogen peroxide solution, wherein the cathode included a substrate (12), such as carbon felt, along with a catalyst coated thereon, wherein the catalyst included an organic compound such as quinone compounds, that comprised carbon.
Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have substituted the cathode design of Gopal including a carbon felt with a catalyst layer comprising carbon in the method of White et al because Gopal teaches that the catalyst was effective for catalyzing the electrolytic production of hydrogen peroxide.
Regarding claim 12, Gopal teaches (see paragraph [0044]) an alternative substrate comprising high surface area activated carbon powder within the catalyst layer. Gopal defined “high surface area” (paragraph [0041]) as having a surface area in the range of 20-2000 m2/g.
Regarding claim 13, Gopal teaches (see paragraph [0045]) mixing Teflon® (a tradename for polytetrafluoroethylene) into the catalyst layer.
Regarding claim 14, the quinone catalyst of Gopal included substantially no metal. Alternatively, the activated carbon substrate (paragraph [0044], discussed above with respect to claim 12) constituted a catalyst layer comprising essentially no metal.
Claim 27 is rejected under 35 U.S.C. 103 as being unpatentable over White et al (US 5,645,700 A) as applied to claim 1 above, and further in view of Frimann (US 2019/0390354 A1).
White et al teach providing the oxygen at increased pressure (col. 6, lines 2-5).
White et al fail to teach how the oxygen is pressurized.
Within the broader field of electrochemistry, as opposed to hydrogen peroxide electrochemistry, Frimann teaches (see abstract, paragraphs [0025] and [0080]-[0082]) that various known commercially available gas compressors are suitable for use with system including an electrochemical cell. Among those known gas compressors were liquid ring compressors.
Therefore, absent a showing of unexpected results, it would have been obvious to one of ordinary skill in the art to have utilized a known commercially available gas compressor as taught by Frimann, such as a liquid ring compressor, for increasing the pressure of the oxygen gas of White et al. See MPEP 2143.I.A.
Claims 15-17, 19-21, and 29 are rejected under 35 U.S.C. 103 as being unpatentable over White et al (US 5,645,700 A) in view of Porta et al (US 4,319,973 A) with evidence from Liu et al (“Morphological Properties and Electrochemical Performance for Compressed Carbon-fiber Electrodes in Redox Flow Batteries”) for claim 20.
White et al teach (see abstract, fig. 1, col. 5, line 55 to col. 6, line 13 and col. 7, lines 1-20) a method comprising flowing a two-phase solution (made by mixing a liquid (11) and a gas (13)) over an electrode (cathode 4, including catalyst layer 5 and current collector/electrically conductive material 9) in a compartment; electrochemically generating a compound (hydrogen peroxide) in the solution at the electrode; and flow the solution from the electrode through an outlet (14) of the compartment.
The direct teachings of White et al show that the two-phase solution was flowed over the electrode. However, at least some of the two-phase solution would have been expected by one of ordinary skill in the art to have also flowed through at least a portion of the electrode. The catalyst of White et al was only located on the surface of the carbon paper that was adjacent to the membrane, and thus for the solution to react at the catalyst, it inherently must have passed through at least a portion of the electrode in the thickness direction.
White et al fail to teach a step of recirculating at least a portion of the solution from the outlet to the inlet.
Porta et al teach (see abstract, fig. 2, and col. 3, line 67 to col. 4, line 42) a method comprising flowing a solution (16) over a least a portion of a surface area of an electrode (6) in a compartment (7), electrochemically generating a compound (hydrogen peroxide) in the solution at the electrode, flowing a solution from the electrode through an outlet (7b) of the compartment, and recirculating at least a portion of the solution from the outlet of the compartment to the inlet (7a) of the compartment. Porta et al teach that the recirculation may be performed until a desired concentration of the compound is achieved, such as between 0.1 and 10 g/L, which range falls within the claimed range of greater than or equal to 0.2 wt%. 10 g/L is approximately 1 wt%.
Therefore, it would have been obvious to one of ordinary skill in the art to have added the recirculation step of Porta et al to the method of White et al for the purpose of increasing the concentration of the compound (hydrogen peroxide) produced by the method to a desired level.
Regarding claim 16, the recirculation step of Porta et al would have inherently included flowing the recirculated solution over and/or through at least a portion of the surface area of the electrode of White et al.
Regarding claim 17, the method of Porta et al also included withdrawing at least a portion (18) of the solution comprising the compound, wherein the compound is hydrogen peroxide (abstract, fig. 2).
Regarding claim 19, White et al teach (see fig. 1) oxygen gas is provided through a pipe (i.e. manifold) to a single intersection with a flow of water through a pipe (i.e. a manifold) to dissolve the oxygen into the water prior to entry into the electrolytic cell. The oxygen gas became dissolved and/or emulsified into the liquid thereby creating the conditions suitable for hydrogen peroxide formation at the cathode.
Regarding claim 20, White et al teach that the current collector (9), a substrate as claimed, comprised carbon paper (see col. 7, lines 1-10).
White et al do not teach that the carbon paper included non-woven fibers.
Liu et al is cited as evidence showing the structure of carbon materials referred to as carbon cloth, carbon paper, and carbon felt. See Fig. 2 and Table 1. Carbon paper is a non-woven carbon material.
Thus, the evidence of record shows that the carbon paper material of White et al inherently included non-woven carbon fibers.
Regarding claim 21, White et al teach (see col. 7, lines 1-10) depositing a catalyst layer onto the carbon paper substrate.
Regarding claim 29, White et al fail to teach the thickness (i.e. the smallest dimension) of the carbon paper being in the range of 1-5 mm. However, absent a showing of unexpected results, it would have been within the ordinary level of skill in the art to have conducted routine experimentation to determine a suitable thickness of carbon paper for providing sufficient current collection and surface area.
Conclusion
The Office suggests that Applicant consider amending the claims to more clearly define the structure of the electrolysis cell and how the two-phase solution flows through the compartment. In particular, the claim language “flowing the two-phase solution over and through at least a portion of the electrode” is much broader than the pattern of flow and structure seen in the figures. In order to more clearly define the differences in flow between the present disclosure and the prior art, the following is offered as a potential way to define the claimed invention to exclude the flow pattern of White et al: “flowing the two-phase solution through an electrode, wherein the electrode comprises a substrate including non-woven fibers comprising carbon and wherein the electrode extends in a plane direction and has a thickness orthogonal to the plane direction, wherein the flow enters the electrode in a direction parallel to the plane direction”. Similar language defining the entry of the two-phase solution along an edge of the electrode and flowing through the electrode in a direction orthogonal to the thickness (or “smallest dimension” as recited in the specification) would also be indicative of the difference in structure of the inventive device in comparison to the prior art of record (this example provided to show that the exact language in these suggestions is not an absolute requirement).
These suggestions have not been evaluated with respect to the prior art beyond the disclosure of the references already of record, such that the suggestions should not be taken as an indication of allowable subject matter.
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 HARRY D WILKINS III whose telephone number is (571)272-1251. The examiner can normally be reached M-F 9:30am -6:00pm.
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/HARRY D WILKINS III/Primary Examiner, Art Unit 1794
