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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 01/05/2026 has been entered.
Status of Rejections
The rejection(s) of claim(s) 24 is/are obviated by applicant’s cancellation.
The rejection of claim(s) 1-10 and 12-14 under 35 USC 103 is/are withdrawn in view of applicant’s arguments.
The previous rejections of claim(s) 21-23 and 25-27 are withdrawn in view of applicant’s amendments/arguments.
New grounds of rejection are presented herein.
Claims 1-10, 12-14, 21-23 and 25-28 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 21-23 and 27 are rejected under 35 U.S.C. 103 as being unpatentable over Hu et al. (“Capture and electrochemical conversion of CO2 to ultrathin graphite sheets in CaCl2-based melts”, J. Mater. Chem. A, 2015) in view of Ito et al. (JP 2010053425 A, citations based on translation), and further in view of Jiao et al. (CN 105624722 A, citations based on translation).
Regarding claim 21, Hu teaches a system comprising:
an electrochemical cell (see e.g. Fig. 6a, three electrode electrochemical workstation; Page 21212, Col. 1, bottom paragraph, lines 1-4) comprising,
a crucible having an initial molten CaCl2:CaO mixture therein (see e.g. Fig. 6a, alumina crucible containing molten CaCl2-CaO), wherein a cathode and an inert anode are positioned in the initial molten CaCl2:CaO mixture (see e.g. Fig. 6a, inert RuO2-TiO2 anode and stainless steel cathode; Page 21212, Col. 1, under “Experimental”, lines 3-4 and 9-11), and
an inlet for feeding carbon dioxide gas into the initial molten CaCl2:CaO mixture (see e.g. Fig. 6a, CO2 inlet at top); and
a furnace having an inert atmosphere therein, wherein the electrochemical cell is sealed in the furnace having the inert atmosphere (see e.g. Fig. 6a, sealed vertical tubular reactor containing the alumina crucible to be heated under argon atmosphere, argon being inert; Page 21212, Col. 1, under “Experimental”, lines 12-14, and Page 21214, Col. 2, lines 18-20).
Hu does not explicitly teach the initial molten mixture also comprising CaCO3, but does discuss carbonate ions being added to the CaCl2 melt by addition of CaCO3 (see e.g. Page 21214, Col. 2, bottom paragraph, lines 21-23).
Ito teaches a system for electrolytic fixation of carbon dioxide as carbon in a bath of molten salt (see e.g. Paragraph 0001), wherein the molten salt comprises an alkali or alkali earth metal halide such as CaCl2 as the main salt, an oxygen ion source such as CaO and a carbonate ion source such as CaCO3 (see e.g. Paragraph 0013, lines 2-6 and Paragraphs 0014-0015), wherein addition of the carbonate ion to a saturated or near-saturated state allows the carbon precipitation reaction at the cathode to proceed smoothly (see e.g. Paragraph 0017, lines 2-3).
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 initial molten mixture of Hu to further comprise CaCO3 as a carbonate source as taught by Ito to allow the carbon precipitation reaction at the cathode to proceed smoothly. MPEP § 2143(I)(A) states that “combining prior art elements according to known methods to yield predictable results” may be obvious. The claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination would yield nothing more than predictable results.
Modified Hu does not explicitly teach a composition of the initial molten CaCO3:CaCl2:CaO mixture comprising less than about 20 weight% CaO, but does teach the CaO contributing to capture of the CO2 (see e.g. Hu Abstract and Page 21213, Col. 4-7).
Jiao teaches a system for electrochemical conversion of carbon dioxide to graphene or carbon nanotubes in a molten salt electrolyte (see e.g. Paragraphs 0002 and 0009), wherein the molten salt may comprise CaCl2 as a main matrix electrolyte (see e.g. Paragraphs 0009 and 0012) with 1-20 wt% of a collector, i.e. for capture, such as CaO (see e.g. Paragraph 0013).
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 initial molten mixture of modified Hu to comprise the CaO in an amount of 1-20 wt%, i.e. less than about 20 wt%, as taught by Jiao as a suitable amount of a collector/capture agent such as CaO in a CaCl2 matrix molten salt electrolyte for electrochemical conversion of CO-2 to solid carbon materials. MPEP § 2143(I)(A) states that “combining prior art elements according to known methods to yield predictable results” may be obvious. The claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination would yield nothing more than predictable results.
Regarding claim 22, modified Hu does not teach the inert anode comprising a metal selected from the group consisting of: tungsten, platinum, nickel and molybdenum, instead teaching it comprising RuO2-TiO2 (see e.g. Hu Page 21212, Col. 1, under “Experimental”, lines 3-4).
Jiao further teaches inert anodes being used for the molten salt electrochemical carbon dioxide conversion to carbon, wherein the inert anode may comprise a composite material of RuO-2 with another oxide such as TiO2 and NiO2 (see e.g. Jiao Paragraphs 0008-0010 and 0016).
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 RuO2-TiO2 inert anode of modified Hu to instead comprise RuO2 with NiO2 as taught by Jiao as an alternate suitable composite inert anode material for use in a molten salt electrochemical carbon dioxide conversion to carbon. MPEP § 2143(I)(B) states that “simple substitution of one known element for another to obtain predictable results” may be obvious. Further, MPEP § 2144.07 states “The selection of a known material based on its suitability for its intended use supported a prima facie obviousness determination in Sinclair & Carroll Co. v. Interchemical Corp., 325 U.S. 327, 65 USPQ 297 (1945)”.
Regarding claim 23, Hu as modified by Jiao teaches the metal having an oxidized surface (see e.g. Jiao Paragraph 0016, inert anode, including the surface thereof, comprising the metal oxides).
Regarding claim 27, modified Hu teaches the furnace being configured to heat the crucible to an effective temperature to maintain the CaCO3:CaCl2:CaO as a molten mixture and to allow carbon to form at the cathode, the effective temperature being 850 degrees Celsius (see e.g. Hu Page 21212, Col. 1, under “Experimental”, lines 12-15, and Page 21213, Col. 1, lines 8-9, and Col. 2, bottom paragraph, lines 5-8, reactor containing molten CaCl2-CaO in crucible heated to 850° C for electrolysis, during which carbon is deposited at the cathode).
Claims 25-26 is rejected under 35 U.S.C. 103 as being unpatentable over Hu, Ito and Jiao, as applied to claim 21 above, and further in view of Ijije et al. (Electro-deposition and re-oxidation of carbon in carbonate-containing molten salts”, Faraday Discuss., 2014).
Regarding claim 25, modified Hu teaches all the elements of the system of claim 21 as stated above. Modified Hu does not explicitly teach a composition of the initial molten CaCO3:CaCl2:CaO mixture comprising greater than 1 weight % up to about 35 weight% of the total composition, only teaching the carbonate preferably being saturated or near saturated in the molten mixture to allow the carbon deposition to proceed smoothly (see e.g. Ito Paragraph 0017, lines 2-3). Hu does teach an amount of 1.4 wt% CaCO3 being added to CaCl2 (see e.g. Hu caption of Fig. 8).
Ijije teaches a system for electrochemical deposition of carbon in molten salts under CO2 atmospheres (see e.g. Abstract), wherein the molten mixture comprises CaCl2 and CaCO3 in a molar ratio of 84:16 (see e.g. Page 107, lines 15-17), equal to about 14.7 wt% CaCO3 in CaCl2.
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 initial molten mixture of modified Hu to comprise 14.7 wt% CaCO3 as taught by Ijije as a suitable amount of CaCO3 in CaCl2 for electrochemical deposition of carbon in molten salts, which is closer to saturation than the smaller amount of Hu. MPEP § 2143(I)(A) states that “combining prior art elements according to known methods to yield predictable results” may be obvious. The claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination would yield nothing more than predictable results.
Regarding claim 26, modified Hu teaches all the elements of the system of claim 21 as stated above. Hu as modified by Jiao further teaches a composition of the initial molten CaCO3:CaCl2:CaO mixture comprising 1 to 20 weight%, i.e. less than about 20 weight% CaO (see e.g. Jiao Paragraph 0013), and a balance weight% of CaCl2 (see e.g. Hu Page 21212, Col. 1, under “Experimental”, lines 12-14, and Page 21217, Col. 2, lines 3-5 and 9-11, CaCl2 as the base melt; Ito Paragraph 0013, lines 2-4, alkali or alkali earth metal halide as main molten salt).
Modified Hu does not explicitly teach a composition of the initial molten CaCO3:CaCl2:CaO mixture comprising greater than 1 weight % up to about 35 weight% of the total composition, only teaching the carbonate preferably being saturated or near saturated in the molten mixture to allow the carbon deposition to proceed smoothly (see e.g. Ito Paragraph 0017, lines 2-3). Hu does teach an amount of 1.4 wt% CaCO3 being added to CaCl2 (see e.g. Hu caption of Fig. 8).
Ijije teaches a system for electrochemical deposition of carbon in molten salts under CO2 atmospheres (see e.g. Abstract), wherein the molten mixture comprises CaCl2 and CaCO3 in a molar ratio of 84:16 (see e.g. Page 107, lines 15-17), equal to about 14.7 wt% CaCO3 in CaCl2.
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 initial molten mixture of modified Hu to comprise 14.7 wt% CaCO3 as taught by Ijije as a suitable amount of CaCO3 in CaCl2 for electrochemical deposition of carbon with CO2 in molten salts, which is closer to the desired saturation than the smaller amount of Hu. MPEP § 2143(I)(A) states that “combining prior art elements according to known methods to yield predictable results” may be obvious. The claimed elements were known in the prior art and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, and the combination would yield nothing more than predictable results.
Allowable Subject Matter
Claims 1-10, 12-14 and 28 contain allowable subject matter.
The following is a statement of reasons for the indication of allowable subject matter: The prior art does not disclose nor render obvious all of the cumulative limitations of claim(s) 1 and 28 with special attention given to the limitation claiming “a surface area of the inert anode is at least five-fold larger than a surface area of the cathode”. The closest prior art is Hu and Dimitrov et al. (“A feasibility study of scaling-up the electrolytic production of carbon nanotubes in molten salts”, Electrochimica Acta, 2002).
Hu teaches a system comprising an electrochemical cell (see e.g. Fig. 6a, three electrode electrochemical workstation; Page 21212, Col. 1, bottom paragraph, lines 1-4) comprising a crucible having a molten CaCl2:CaO mixture therein (see e.g. Fig. 6a, alumina crucible containing molten CaCl2-CaO), wherein a cathode and an inert anode are positioned in the molten CaCl2:CaO mixture (see e.g. Fig. 6a, inert RuO2-TiO2 anode and stainless steel cathode; Page 21212, Col. 1, under “Experimental”, lines 3-4 and 9-11). Hu does not teach a surface area of the inert anode being at least five-fold larger than a surface area of the cathode.
Dimitrov teaches a method and apparatus for electrolytic production of carbon nanotubes in molten salts (see e.g. Abstract), in which an anode surface area is over 60 times larger than a cathode surface area to provide a relatively constant cathode potential and current density (see e.g. Page 92, connecting paragraph of Col. 1 and Col. 2, lines 5-15, and Page 93, Col. 1, under “Experimental”, lines 22-25). However, the system of Dimitrov differs from that of Hu in that it produces carbon nanotubes by electrolytic consumption of carbon electrodes, whereas Hu forms carbon by injection of CO2 coupled with carbon, and would therefore not necessarily garner the same benefits from the constant current density provided by the change in relative anode/cathode surface area. Further, Hu identifies variation in current density as a useful measure of the process (see e.g. Hu Page 21212, Col. 2, under “Results and discussion”, lines 1-3) and would therefore be even less inclined to make a modification that removes said variation.
There is no teaching or motivation that makes providing a surface area of the inert anode of Hu at least five-fold larger than a surface area of the cathode obvious.
Response to Arguments
Applicant’s arguments, see page 7, filed 01/05/2026, with respect to the rejection(s) of claim(s) 1 under 35 USC 103 over Hu in view of Ito and Dimitrov, particularly the reversal by PTAB, have been fully considered and are persuasive. The rejection of claim 1 has been withdrawn.
Applicant’s arguments, see pages 8-9, filed 01/05/2026, with respect to the rejection(s) of amended claim(s) 21 under 35 USC 103 over Hu in view of Ito, particularly regarding the incorporation limitation from now cancelled claim 24 for which the rejection was reversed by PTAB, 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 Hu, Ito and Jiao.
Conclusion
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/M.S.J./Examiner, Art Unit 1795
/LUAN V VAN/Supervisory Patent Examiner, Art Unit 1795