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 Amendments
This is a final office action in response to applicant's arguments and remarks filed on 04/20/2026.
Status of Rejections
All previous rejections are maintained and modified only in response to the amendments to the claims.
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 monotonically 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 monotonically 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, said concentration gradients being formed by interdiffusion of tin from the first catalytic layer into the second catalytic layer and platinum from the second catalytic layer into the first catalytic layer during said thermal treatment. 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 in the direction of, i.e. toward, the outer surface of each layer (see e.g. Fig. 3, respective metal components including Pt and Sn diffusing between the layers with concentrations monotonically decreasing in respective directions; 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 monotonically 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 filed 04/20/2026 have been fully considered but they are not persuasive.
On pages 8-10, Applicant argues that Cho only discloses localized interfacial diffusion between adjacent layers and does not teach or suggest a monotonic decrease across substantially the entire thickness of a layer, forming a layer-wide directional gradient. This is not considered persuasive. The claims as written do not require the concentration decreases/gradients to extend across the entire thickness of the respective layer, instead they only require that the concentration decreases “from the interface with said first catalytic layer toward the outer surface of the second catalytic layer” and “from the interface with said second catalytic layer toward the substrate”. Cho teaches the concentrations of the metal ions of each initial layer being present in the opposite layer at a monotonically decreasing concentration in the direction of, i.e. toward, the outer surfaces of the respective layers (see e.g. Cho Fig. 3, respective metal components including Pt and Sn diffusing between the layers with concentrations monotonically decreasing in respective directions; Paragraphs 0011, 0024, and 0054).
Conclusion
THIS ACTION IS MADE FINAL. 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.
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/M.S.J./Examiner, Art Unit 1795
/LUAN V VAN/Supervisory Patent Examiner, Art Unit 1795
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