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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 07/07/2025 has been entered.
Status of Rejections
All previous rejections are withdrawn in view of applicant’s amendments.
New grounds of rejection are necessitated by applicant’s amendments.
Claims 1, 3-9 and 13-15 are pending and under consideration for this Office Action.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1, 3-9 and 13-14 are rejected under 35 U.S.C. 103 as being unpatentable over Haneda et al. (U.S. 2013/0334037) in view of Ohta et al. (U.S. 2008/0035491), and further in view of Cho et al. (KR 20170093039 A, citations based on translation).
Regarding claim 1, Haneda teaches an electrode for gas evolution in electrolytic processes (see e.g. Fig. 4, electrode for electrolysis 100, e.g. as anode for chlorine evolution; Paragraph 0040, line 1, and Paragraph 0015, lines 1-5) comprising
a valve metal substrate (see e.g. Fig. 4, conductive substrate 10 preferable comprising titanium, which is a valve metal; Paragraph 0042, lines 1-4) and
a coating comprising
a first catalytic layer formed on said substrate containing a mixture of iridium and ruthenium oxides (see e.g. Fig. 4, first layers 20 on both surfaces of conductive substrate 10 comprising ruthenium and iridium oxide; Paragraph 0040, lines 3-4, and Paragraph 0045, lines 5-8), obtained from precursors containing said iridium and ruthenium in the form of organometallic complexes (see e.g. Paragraph 0070 and Paragraph 0071, lines 1-2, first layer obtained from solution containing salt of ruthenium and iridium, such as a metal alkoxide, which is an organometallic complex), and
a second catalytic layer formed on said first catalytic layer containing platinum (see e.g. Fig. 4, second layers 30 comprising platinum coated on first layers 20; Paragraph 0040, lines 4-5, and Paragraph 0051, lines 1-2).
Haneda does not explicitly teach the first catalytic layer containing tin or its oxide, obtained from a precursor containing said tin in the form of an organometallic complex, but does teach that it may comprise other compositions including at least one of ruthenium, iridium and titanium oxides, such as a DSA oxide composition that includes tin (see e.g. Paragraph 0048), as well as metal oxide components in the layer generally being obtained by thermal decomposition of salts of the metal, such as an organometallic metal alkoxide salt (see e.g. Paragraph 0067, lines 10-16, and Paragraph 0071, lines 1-2).
Ohta teaches an electrode for electrolysis (see e.g. Abstract) comprising an intermediate layer formed between an electrode active layer comprising Pt and/or Pd and a base material (see e.g. Paragraph 0019, lines 3-6, and Paragraph 0022, lines 1-4), the intermediate layer containing a mixed metal oxide of one or more metals such as Ir, Ti and/or Ru and an oxide of Sn (see e.g. Paragraph 0019, lines 6-10), the inclusion of the Sn oxide with the other mixed metal oxides provides the electrode with excellent corrosion resistance and an ability to endure sustained use in electrolysis (see e.g. Paragraph 0019, lines 10-17).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the first catalytic layer of Haneda to comprise tin oxide, similarly obtained from a precursor salt such as an organometallic metal alkoxide, in addition to the ruthenium, iridium and titanium oxides as taught by Ohta to provide the electrode with excellent corrosion resistance and an ability to endure sustained use in electrolysis.
Modified Haneda does not explicitly teach the first catalytic layer containing platinum or its oxide and the second catalytic layer containing tin or its oxide, wherein said tin of the second catalytic layer is present in a concentration decreasing from the interface with said first catalytic layer toward the outer surface of the second catalytic layer, wherein said platinum in the first catalytic layer is present in a concentration decreasing from the interface with said catalytic layer toward the substrate, and wherein the electrode is subjected to a final thermal treatment to induce diffusion between the catalytic layers. Haneda does however teach the desire to maintain a low electrolysis voltage, such electrolysis voltage including that caused by structural resistance of an electrolysis cell including the electrode (see e.g. Haneda Paragraph 0002, lines 4-10).
Cho teaches an electrode with a double-layer structure on a support (see e.g. Paragraph 0001, lines 1-2, and Paragraph 0008) comprising a first layer including PtO2 and a second layer including SnO2 (see e.g. Paragraph 0009, lines 1-4), wherein a concentration gradient of metal ions of the respective layers is formed near the interface between the layers by a diffusion heat treatment, causing the metal ions of each layer to be present in the opposite layer at a decreasing concentration from the interface (see e.g. Fig. 3, respective metal components including Pt and Sn diffusing between the layers; Paragraphs 0011, 0024, and 0054), this diffusion treatment and resulting concentration gradient minimizing electrical resistance otherwise caused by a heterojunction between the layers and maintaining high electron mobility, i.e. conductivity (see e.g. Paragraphs 0028 and 0041-0042).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the electrode of modified Haneda to comprise a concentration gradient of components including Pt from the second layer and Sn from the first layer present in a decreasing concentration from the interface in the opposite layer as a result of a diffusion heat treatment as taught by Cho to minimize electrical resistance between the layers and maintain high electron mobility, i.e. conductivity.
Regarding claim 3, modified Haneda teaches said second catalytic layer containing less than Pt= 50-95.2% in the form of metal in molar percentage referred to the metal (see e.g. Haneda Paragraph 0010, Pt present in 1 to 20 mol with respect to 1 mol Pd, equal to 50 to 95.2 mol%, minus a small amount assumed to diffuse to the first layer as stated above), overlapping the claimed range of the present invention. MPEP § 2144.05 I states “In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists.”
Regarding claim 4, modified Haneda teaches said second catalytic layer containing more than Pd=0.8-50% in the form of metal in molar percentage referring to the metal (see e.g. Haneda Paragraph 0010, Pt present in 1 to 20 mol with respect to 1 mol Pd, resulting in 0.8-50 mol% Pd, a small amount of Pt assumed to diffuse to the first layer as stated above and thereby increase the relative mol% of Pd), overlapping the claimed range of the present invention (see MPEP § 2144.05 I as cited above).
Regarding claim 5, the electrode of Haneda as modified by Ohta, which would experience temperature induced diffusion of Sn between the catalytic layers as describe above, therefore teaches said second catalytic layer containing greater than 0% Sn in average molar percentage based on the metal, overlapping the claimed range of the present invention (see MPEP § 2144.05 I as cited above).
Regarding claim 6, Haneda as modified by Ohta teaches said iridium, ruthenium and tin oxides of said first catalytic layer being present in molar percentages of approximately Ru=4.78-26.4%, Ir=1.60-27.0%, and Sn= 33.1-75.3% referring to the metal (calculated from preferred Ir:Ru:Ti molar ratio of 0.2-1:1:1-8 and Sn weight% of 50-80%; see e.g. Haneda Paragraph 0022 and Ohta Paragraph 0020, amounts assumed to be slightly increased or decreased based on diffusion of Pt and Sn described above), overlapping the claimed ranged of the present invention (see MPEP § 2144.05 I as cited above)
Regarding claim 7, Haneda as modified by Ohta teaches said first catalytic layer also containing titanium oxides in molar percentage Ti=4.93 to 58.8% referred to the metal (calculated from preferred Ir:Ru:Ti molar ratio of 0.2-1:1:1-8 and Sn weight% of 50-80%; see e.g. Haneda Paragraph 0022 and Ohta Paragraph 0020, amounts assumed to be slightly increased or decreased based on diffusion of Pt and Sn described above), encompassing the claimed range of the present invention (see MPEP § 2144.05 I as cited above).
Regarding claim 8, the electrode of Haneda as modified by Ohta, which would experience temperature induced diffusion of Pt between the catalytic layers as describe above, therefore teaches said second catalytic layer containing greater than 0% Pt in average molar percentage based on the metal, overlapping the claimed range of the present invention (see MPEP § 2144.05 I as cited above).
Regarding claim 9, modified Haneda teaches the valve metal substrate being titanium (see e.g. Haneda Paragraph 0042, lines 1-4).
Regarding claim 13, modified Haneda teaches a cell for electrolysis of solutions of alkaline chlorides (see e.g. Haneda Fig. 5, electrolytic cell 200 comprising sodium or potassium chloride solutions as electrolyte; Paragraph 0063, lines 1-4, and Paragraph 0064, lines 1-3) comprising an anodic compartment and a cathodic compartment (see e.g. Haneda Fig. 5, anode chamber containing anode 230 on left and cathode chamber containing cathode 240 on right; Paragraph 0063, lines 6-12), wherein the anodic compartment is equipped with the electrode according to claim 1 (see e.g. Haneda Paragraph 0063, lines 1-3, inventive electrode for electrolysis as the anode).
Regarding claim 14, modified Haneda teaches said anodic compartment and said cathodic compartment being separated by an ion-exchange membrane (see e.g. Haneda Fig. 5, ion-exchange membrane 250; Paragraph 0063, lines 9-12).
Claim 15 is rejected under 35 U.S.C. 103 as being unpatentable over Haneda, Ohta and Cho, as applied to claim 13 above, and further in view of Swiegers et al. (U.S. 2018/0363154).
Regarding claim 15, modified Haneda teaches all the elements of the cell of claim 13 as stated above. Modified Haneda does not explicitly teach an electrolyzer for the production of chlorine and alkali from alkali chloride solutions comprising a modular arrangement of cells, wherein each cell is the cell according to claim 13. Haneda does however teach the cell being used for the production of chlorine from alkali chloride solutions (see e.g. Haneda Paragraph 0015, lines 1-5, and Paragraph 0064, lines 1-3).
Swiegers teaches a stacked electrochemical cell (see e.g. Paragraph 0063, lines 6-11), i.e. electrolyzer, comprising modular reactor cell units engineered to be attached to other identical modular unit, to thereby seamlessly enlarge the overall reactor to the extent required (see e.g. Paragraph 0066, lines 1-5).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified the cell of modified Haneda to be attached to other identical cells to form a modular electrolyzer as taught by Swiegers to enable seamless enlargement of the overall electrochemical reaction system.
Response to Arguments
Applicant’s arguments, see pages 8-9, filed 07/07/2025, with respect to the rejection(s) of amended claim(s) 1 under 35 USC 103 over Haneda in view of Ohta, particularly regarding the concentration gradients produced by the final thermal treatment, have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Haneda, Ohta and Cho.
On page 9, Applicant argues that Haneda discourages interlayer diffusion. This is not considered persuasive. Paragraph 0088 of Haneda simply states that the first layer is not corroded or eluted during the thermal decomposition to form the second layer, which does not explicitly discourage any further post treatment which may cause interdiffusion.
On pages 9-10, Applicant argues that there is no teaching or suggestion to include tin from an organometallic complex in the first catalytic layer. This is not considered persuasive. Haneda teaches that the first catalytic layer may comprise other compositions including at least one of ruthenium, iridium and titanium oxides, such as DSA oxide composition that includes tin (see e.g. Haneda Paragraph 0048), as well as metal oxide components in the layer generally being obtained by thermal decomposition of salts of the metal, such as an organometallic metal alkoxide salt (see e.g. Haneda Paragraph 0067, lines 10-16, and Paragraph 0071, lines 1-2). There is therefore motivation to use such an organometallic precursor of tin in the composition of Haneda as modified by Ohta.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Cao et al. (U.S. 2009/0242417) discloses a process of manufacturing electrodes for electrolysis wherein an extremely high bonding effect is obtained between an oxide interlayer and an outer catalyst layer due to mutual heat diffusion of their respective constituent components at their joint interface during a heat sintering process.
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/M.S.J./Examiner, Art Unit 1795
/LUAN V VAN/Supervisory Patent Examiner, Art Unit 1795