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 .
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
Information Disclosure Statements
The Information Disclosure Statement filed on 17 March 2026 has been received and considered by the Examiner.
Amendment
Applicant’s amendments to the claims filed on 17 March 2026 have been entered and considered for this action.
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 1-6, 10, 12-18, 20, 27, 36, and 38-40 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the enablement requirement. The claims contains subject matter which was not described in the specification in such a way as to enable one skilled in the art to which it pertains, or with which it is most nearly connected, to make and/or use the invention.
The broadest reasonable interpretation of claim 1 covers contacting any of the recited iron-containing coal combustion products, which have can have widely varied composition, with any CO2 source or CO2 precursor and water to produce H2 in the absence of external heating, wherein the pressure in the reactor reaches a pressure from 40 Bar to 350 Bar. The specification does not provide direction on how to effect the transformation of water into hydrogen in the absence of an identified a chemical reductant at low-temperatures.
At the time of filing, the state of the art was such that there was a limited number of fundamental ways to transform water into hydrogen: thermochemical, photochemical, and electrochemical water splitting (Eq. 1 and Fig. 1) or chemical or electrochemical reduction using an external source of electrons (Eq. 2).
H-2O [Wingdings font/0xE0] H2 + ½ O2 (1)
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Fig. 1: Brief summary of hydrogen production technologies from water decomposition (Zhou et al. Next Energy 2025, 8, 100270.)
H2O + 2e- [Wingdings font/0xE0] H2 + O2- (2)
The specification and claims do not point toward either the photolysis or electrolysis water splitting processes because no source of light or of electricity is mentioned in the discussion of the invention. The thermochemical water-splitting pathway is also ruled out, as this process is highly endothermic and typically is carried out at or above 500 °C with the input of heat (https://www.energy.gov/eere/fuelcells/hydrogen-production-thermochemical-water-splitting), while no external heat is supplied in the process of claim 1; additionally, claims 2 and 3 and paragraph [0013] each teach that the process occurs below 100 °C and as low as -30 °C. The specification also gives no indication that oxygen is formed in the course of the reaction.
This leaves an external chemical reductant as the only mechanism that one of ordinary skill in the art would recognize as being able to effect the transformation described in claim 1, yet no reasonable reductant is identified among the limitations of the claim or in the specification. In fact, while paragraphs [0003]-[0005] and [0008]-[0010] identify chemical reductants for related processes, [0014] describes that the current invention unexpectedly works with high-valent iron oxides; indeed, such materials are not expected to function as reductants and it is unclear how they would do so. Furthermore, claim 1 requires that the iron-containing material be a “coal combustion product” and one of ordinary skill in the art would recognize that a “combustion product” means materials which have already been subjected to combustion (oxidation with oxygen), and therefore would afford very little or no reducing power. The mechanism by which the claimed invention functions, the identity of the critical elements, and how to successfully carry out the process of the invention is therefore obscured.
Accordingly, the ordinarily skilled artisan before the effective filing date of the claimed invention would not be apprised how to make or use the invention as claimed without undue experimentation, as supported by analysis of the Wands Factors (MPEP 2164.01) and the record as a whole:
Breadth of the claims: The broadest reasonable interpretation of claim 1 covers contacting any of the recited iron-containing coal combustion products and any CO2 source or CO2 precursor with water to produce H2 in the absence of external heating, where the pressure of the reactor (at some point) reaches a value from 40 bar to 350 bar. The compositions of the iron-containing coal combustion products recited in the claim can be quite broad, but the composition of these products is necessarily critical if the invention is to function according to principals recognized in the art, which teach that a reductant is necessary to carry out the transformation of water to hydrogen at the temperatures described and claimed. An alternative possibility is that the invention functions by reaction with the walls of the reactor, and indeed all reactor compositions are covered by the claims but this mechanism is not discussed in the specification.
Nature of the invention: The nature of the invention in this case is peculiar, as it seem to imply the reduction of water to hydrogen without a chemical or electrochemical reductant and in the absence of high temperatures or a light source, at least one of which would be understood as required by one of ordinary skill in the art.
State of the prior art: The prior art has many examples of converting water and carbon dioxide to hydrogen (e.g., [0003]-[0005] and [0008]-[0010]), but all require an external reductant like metallic iron, for example. The prior art provides no examples of using fully oxidized materials to reduce water, and thus one of ordinary skill in the art would not know where to begin experimenting.
Level of one of ordinary skill: The level of one of ordinary skill in the art would be one experienced in the theoretical and practical aspects of reactions to make hydrogen. Many practicing in this field will have advanced degrees. Nevertheless, they would find it challenging to find the right conditions for carrying out the invention when the prior art all teaches away from low-temperature water splitting without a reductant.
Level of predictability in the art: The rates of chemical reactions and effectiveness of heterogeneous catalysts is highly variable and subject to many parameters, such as composition, level and identity of impurities, particle size, and surface area, to name a few. In the instant case, the composition of the materials are unknown and the products of coal combustion can be highly variable depending on the source of the coal and the conditions of combustion (https://en.wikipedia.org/wiki/Coal_combustion_products). The high degree of variability in the compositions of encompassed by “iron-containing coal combustion products” of the instant claims, even when limited to those particular sources recited in claim 1, introduces a high potential for undue experimentation to find the right composition of materials capable of effecting the claimed transformation. If the reactor itself is involved in the chemical transformation, the possible variations are even greater.
Amount of direction provided by the inventor: The instant specification and claims do not provide much direction on how to successfully implement the invention and carry out what seems to be a thermodynamically impossible reaction. In particular, the inventor provides no balanced chemical reaction which might guide one of ordinary skill in determining how the invention functions or what types of inputs might be necessary in order to make the invention work.
Existence of working examples: The specification provides three numbered examples, pages 29-31, but each example uses the same input materials: “iron waste from a coal fired power plant (‘iron slag’)”, technical grade carbon dioxide, and water. While the elemental analysis of the ‘iron slag’ is provided for the material used in Example 1, there is no indication to one of ordinary skill in the art what the actual components of the ‘iron slag’ are. Even in the data provided in Table 1 (p. 30), it is unclear if the fractions reported correspond to masses of the individual elements, or masses of the oxides of those elements. For example, one of ordinary skill in the art would expect the combustion product of Si to be SiO2, but if 55% of the ‘iron slag’ is Si, and this Si is tied up in SiO2, then 118% of the mass is accounted for in SiO2 alone, a physical impossibility.
Quantity of experimentation needed: To use the invention based on the content of the disclosure one of ordinary skill would need to find the precise iron-containing coal combustion product that allows the invention to function. There are a huge number of coals available from all over the world, each with different compositions, even more conditions under which they can be combusted, and various products of each combustion reaction. Furthermore, the claims and specification provide that the iron-containing coal combustion product comprises high-valent iron compounds, which are thermodynamically incapable of reducing water to hydrogen. One of ordinary skill would thus be left to experimenting with various types of coal under a near infinite set of combustion conditions to arrive at the claimed invention capable of carrying out the reduction of water and carbon dioxide to hydrogen.
As a result of the peculiar reaction being claimed and the unexplained mechanism by which the invention functions, undue experimentation would be required by one of ordinary skill in the art to practice the invention recited in the claims. In particular, because no direction has been provided on which particular coal combustion product compositions would be effective at carrying out the reduction process recited in claim 1, because the fully oxidized materials implied by the claims and specification should be incapable of producing the claimed reaction, and because the composition of coal-combustion products is highly variable, one of ordinary skill would be unable to carry out the claimed process.
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 applicant regards as his invention.
Claims 1-6, 10, 12-18, 20, 27, 36, and 38-40 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 1 recites the limitations "the reactor" and “the internal pressure” in line 7. There is insufficient antecedent basis for these limitations in the claim.
Claims 2-6, 10, 12-18, 20, 27, 36, and 38-40 each depend upon claim 1 and are likewise rejected.
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.
Claims 1-6, 10, 12-18, 27, 36, 38, and 40 are rejected under 35 U.S.C. 103 as being unpatentable over Barenbaum et al. (WO 2014/067536 A2) in view of Wang (Environ. Sci. Technol. 2008, 42, 7055–7063) and Schure et al. (Environ. Sci. Technol. 1985, 19, 82-86), and with respect to claim 27 as evidenced by Mohammadian et al. (J. CO2 Utilization 2023, 21, 102463). The provided English machine translation of Barenbaum (WO 2014067536 A2) is referenced in the analysis below.
Regarding claim 1, Barenbaum teaches a process for producing H2 ([0001]), the process comprising a step of contacting water, a CO-2 source consisting of CO2 ([0015]) and a catalyst ([0016]) thereby producing H2 ([0017]), where the process is performed in a reactor ([0015]) in the absence of external heating (without the supply of additional energy; [0025]).
Barenbaum further teaches that metals, alloys, minerals and solutions can be used as catalysts ([0019]), that it is preferable to use porous materials as catalysts ([0040]), and that it should be expected that the use of catalysts made from other materials, including, in addition to metals also SiO2, will increase efficiency [0065]. One specific embodiment taught by Barenbaum uses iron-containing materials (sedimentary rocks containing SiO2 as well as iron and its main oxides; [0040]) as the catalyst. Barenbaum does not explicitly teach an iron-containing coal combustion product in the process, as required by the instant claim, or the internal pressure of the reaction reaching a value from 40 bar to 350 bar.
However, Wang teaches that iron-containing coal combustion product (fly ash) have shown good catalytic activities for H2 production (abstract and Section 3.1) and that fly ash is comprised of SiO2 and Fe2O3, which could be used an effective catalyst component (p. 7055, column 2, paragraph 2). Furthermore, Schure teaches that coal fly ash is nanoporous (abstract).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use in the process of Barenbaum the iron-containing combustion product of fly ash as either a catalyst support or for its Fe2O3 catalyst component, as taught by Wang, thereby arriving at the instantly claimed invention.
One of ordinary skill in the art would have been motivated to do so because Barenbaum teaches that the catalysts to be used in their process can be varied and include SiO2 and iron oxides, and Wang teaches that fly ash has these components and also that they could prove effective catalysts. One would have been alternatively motivated to use fly ash as a catalyst support for another hydrogen producing catalyst because Wang teaches that fly ash serves as a good support for catalysts that produce the desired hydrogen product. In either case, one of ordinary skill would have been further motivated to use fly ash because Barenbaum teaches that porous catalysts are preferable and Schure teaches that fly ash is porous.
Regarding the pressure in the reactor, Barenbaum teaches initial pressures of up to 10 atm (10.1 bar), that the pressure in the reactor increases over time, and that increases more the higher the initial pressure ([0049]) Barenbaum further teaches their system reaching a pressure of 17 bar in 6 hours when starting at 10 bar, and a pressure of 19 bar in 28 hours when starting at 6 bar.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have optimized by routine experimentation the pressure reached in the reactor by varying both the initial pressure of the system and the reaction time, including to within the claimed range or 40 bar to 350 bar. One of ordinary skill in the art would have been motivated to do so in order to maximize reaction rate and yield of hydrogen while balancing with costs associated with operating at higher pressures or longer times. “[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” See In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). The discovery of an optimum value of a known result effective variable, without producing any new or unexpected results, is within the ambit of a person of ordinary skill in the art. See In re Boesch, 205 USPQ 215 (CCPA 1980). See MPEP § 2144.05(II).
Regarding claim 2 and 3, modified Barenbaum teaches the process of claim 1, where Barenbaum teaches the process being performed at 20-23°C ([0041]), which falls within the ranges recited in claim 2 (100°C or less) and claim 3 (about -5 °C to about 50 °C).
Regarding claim 4, modified Barenbaum teaches the process of claim 1, where Barenbaum teaches the process being performed without the supply of additional energy ([0025]), which includes external electric energy.
Regarding claim 5, modified Barenbaum teaches the process of claim 1, where Barenbaum further teaches a step of collecting the produced H2 (the hydrogen…formed during the chemical reaction enter[s] at least one separator after the reactor; [0017]).
Regarding claim 6, modified Barenbaum teaches the process of claim 1, where Barenbaum further teaches a step of post-treating the produced H2, wherein post-treating comprises separation (the hydrogen…formed during the chemical reaction enter[s] at least one separator after the reactor. The reaction products are separated; [0017]-[0018]).
Regarding claim 10, modified Barenbaum teaches the process of claim 1, where Barenbaum further teaches the water being sea water ([0015]).
Regarding claims 12 and 36, modified Barenbaum teaches the process of claim 1, where Wang further teaches that power plants produce large quantities of fly ash (Section 1, paragraph 1) and that there is interest in using this fly ash for other purposes and to keep it out of the landfills (Section 1, paragraph 2).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to utilize fly ash originating from a power plant, thereby meeting the limitations of claim 12. One of ordinary skill in the art would have been motivated to do so because Wang teaches that there is interest in using this fly ash for other purposes and to keep it out of the landfills. The use of such a coal combustion product would also constitute recycling of the coal combustion product and would therefore also meet the limitations of claim 36.
Regarding claims 13 -15, modified Barenbaum teaches the process of claim 1, where Wang teaches that fly ash comprises the trivalent iron oxide Fe2O3, (Table 1).
Regarding claim 16, modified Barenbaum teaches the process of claim 1, where Wang teaches the fly ash (coal combustion product) containing from 1.1%-29.3% iron oxide, which overlaps with the instantly claimed range of from about 2% to about 40% iron oxide.
It is noted that the courts have stated where the claimed ranges “overlap or lie inside the ranges disclosed by the prior art” a prima facie case of obviousness exists (see In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990); Titanium Metals Corp. of America v. Banner, 778 F2d 775. 227 USPQ 773 (Fed. Cir. 1985) (see MPEP 2144.05.01).
Regarding claim 17, modified Barenbaum teaches the process of claim 1, where Wang teaches the fly ash (coal combustion product) containing from 11.1% to 98.5% silicon dioxide depending on its source, with most countries (excluding Canada and China) producing fly ash with between 22% and about 70.1% silicon dioxide (Table 1). The broader range contains the instantly claimed range, and the narrower range experienced by most countries largely overlaps with the instantly claimed range of from about 25% to about 75%. It is again noted that the courts have stated where the claimed ranges overlap or lie inside the ranges disclosed by the prior art a prima facie case of obviousness exists.
Regarding claim 18, modified Barenbaum teaches the process of claim 1, and further teaches that the greatest effect was observed when the reactor was filled with steel (iron) shavings and that is preferable to use porous materials as catalysts ([0040]). Wang teaches that fly ash serves as a good catalysts support (abstract), which means that materials can be deposited upon it.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use fly ash that has been enriched in iron content in the methods of Barenbaum. One of ordinary skill would have been motivated to do so because Barenbaum teaches that extra iron provides the greatest effect in their process and Wang teaches that fly ash can serve as support for metals such as iron. One of ordinary skill would have been additionally motivated because it is well known in the art that higher catalyst loadings typically increase reaction rates and increasing the iron-content of the fly ash would be increasing the catalytic metals.
Regarding claim 27, modified Barenbaum teaches the process of claim 1, where Barenbaum teaches the use of water carbonated at an initial pressure of at least 2 atm ([0043]), which will generate a solution with a pH less than 6.5, as evidenced by Mohammadian (Fig. 14a).
Regarding claim 30, modified Barenbaum teaches the process of claim 1, where fly ash, which contains the anti-caking agent silicon dioxide, is being added to the reactor, thereby meeting the limitations of claim 30.
Regarding claim 38, modified Barenbaum teaches the process of claim 1, and further teaches a period of time for a reaction between water, the iron-containing coal combustion product, and the CO2 source is 5 hours to 2 days ([0041]), meeting the limitation of at least 60 minutes.
Regarding claim 40, modified Barenbaum teaches the process of claim 1, where Wang teaches the use of fly ash. Wang further teaches that the fly ash products may have total iron oxide content of 0.55 wt% to 29.3 wt% and total silicon dioxide content of 11.1 wt % to 98.5 wt%, depending on the source; excluding the high and low outliers (Canda and China), the typical ranges are 1.1-19 wt% Fe2O3 and 22-70.1 wt% SiO2 (Table 1). Each of these ranges overlaps with the instantly claimed ranges of iron oxide (5-30 wt%) and silicon dioxide (25-75 wt%) content.
It is noted that the courts have stated where the claimed ranges “overlap or lie inside the ranges disclosed by the prior art” a prima facie case of obviousness exists (see In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990); Titanium Metals Corp. of America v. Banner, 778 F2d 775. 227 USPQ 773 (Fed. Cir. 1985) (see MPEP 2144.05.01). Therefore, the claimed ranges merely represent an obvious variant and/or routine optimization of the values of the cited prior art.
Claim 20 is rejected under 35 U.S.C. 103 as being unpatentable over Barenbaum et al. (WO 2014/067536 A2), Wang (Environ. Sci. Technol. 2008, 42, 7055–7063) and Schure et al. (Environ. Sci. Technol. 1985, 19, 82-86), as applied to claim 1, and further in view of Keith et al. (Joule 2018, 2,1573–1594). The provided English machine translation of Barenbaum is referenced in the analysis below.
Regarding claim 20, modified Barenbaum teaches the process of claim 1, where Barenbaum also teaches that the CO2 is supplied from a cylinder of carbon dioxide ([0038]) which can be considered pure industrial CO2. Barenbaum further teaches that emissions of CO2 into the atmosphere are reaching catastrophic proportions, that the issue of disposal of CO2 is very relevant and timely ([0004]), and that the main objective of their invention was to create an effective method for utilization of carbon dioxide ([0013]). Barenbaum also teaches that their method collects a gas mixture containing hydrocarbons ([0039]), which since they are derived from CO2 can be considered a form of CO2 sequestration. Barenbaum does not specifically teach the use atmospheric CO2.
However, Keith teaches that capture of atmospheric CO2 (direct atmospheric capture, DAC) serves as a source of carbon neutral hydrocarbon fuels and allows carbon removal from the atmosphere (Context & Scale, p. 1573), thereby addressing the problem of CO2 emissions identified by Barenbaum.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use atmospheric CO2 from a DAC process as taught by Keith in the method of modified Barenbaum, which would result in atmospheric CO2 sequestration. One of ordinary skill in the art would have been motivated to do so because Barenbaum teaches that emissions of CO2 into the atmosphere need to be addressed and Keith teaches that DAC processes that use atmospheric CO2 help to address them.
Claim 39 is rejected under 35 U.S.C. 103 as being unpatentable over Barenbaum et al. (WO 2014/067536 A2), Wang (Environ. Sci. Technol. 2008, 42, 7055–7063) and Schure et al. (Environ. Sci. Technol. 1985, 19, 82-86), as applied to claim 1, and further in view of Plescia et al. (WO 2011/145080 A1; cited as pertinent prior art in the prior office action and on the IDS filed 8 May 2024). The provided English machine translation of Barenbaum is referenced in the analysis below.
Regarding claim 39, modified Barenbaum teaches the process of claim 1, where Wang teaches the use of fly ash. Neither Barenbaum nor Wang teach the use of iron slag.
However, Plescia teaches a similar process for the production of water and sequestration of CO2 using fly ash (p. 1). Plescia further teaches that in place of fly ash, one can use iron slag (slag from blast furnace iron metallurgy; p. 1, lines 4-8) to perform an analogous reaction.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to replace the fly ash used in the method of modified Barenbaum with iron slag, as taught by Plescia. One of ordinary skill in the art would have been motivated to do so because Plescia teaches that each of these materials is capable of participating in the same desired reaction.
Response to Arguments
The declaration filed under 37 CF § 1.132 on 17 March 2026 has been entered and considered. However, the assertions presented therein are not persuasive.
Items 6-10 of the declaration address the issue raised on page 8 of the prior Office action regarding the problems with Table 1. However, the assertion that “Table 1 reports standard elemental concentrations …and are not normalized to oxide forms” (points 7 and 10) does not appear to be correct.
According to this assertion, Table 1 indicates that a 100 gram sample of the iron slag used in Example 1 contains 55 grams of silicon. However, as previously set forth, and acknowledged in the instant specification [0011] and [0021], the form of silicon that is found in coal combustion products is silicon dioxide, i.e. every silicon atom is paired with two oxygen atoms. It follows from the relative mass of silicon and oxygen (28 amu/Si atom to 16 amu/O atom) that with every 55 g of silicon there is also 63 grams of oxygen; we then arrive at a conclusion that our 100 gram sample of iron slag contains 118 grams of SiO2, a physical impossibility.
It is further noted that Exhibit A, page 2, seems to support that the mass percents of silicon, aluminum, iron are in fact reported as the oxides.
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Items 11-17 of the declaration addresses the obviousness of the claimed invention, however, none of the arguments presented therein are persuasive that the results obtained by the instant method are non-obvious or unexpected in view of the prior art. Table 2 of the declaration, and the associated conclusions, indicate that as initial pressure is increased, the reaction rate accelerates and higher final pressures are reached. This is the same observation made by Barenbaum ([0049] and Fig. 2), as analyzed above. And though Barenbaum operated at lower pressures than instantly claimed, Barenbaum showed that pressure is a result effective variable and one of ordinary skill in the art would have expected the trend to continue. The discovery of an optimum value of a known result effective variable, without producing any new or unexpected results, is within the ambit of a person of ordinary skill in the art. See In re Boesch, 205 USPQ 215 (CCPA 1980). See MPEP § 2144.05(II). The limitations of the instant claim are therefore obvious in view of the prior art.
Items 18-22 address the CO2 uptake abilities of the instant invention, but these feature are not claimed. Additionally, though not relied upon in the rejection of claim 1, Plescia likewise reports significant CO2 uptake by slags and industrial ashes while producing hydrogen (Examples 1-6).
Item 23 reflects the opinion of the inventor that the invention as claimed is enabled by the specification, but no evidence or arguments directed at the inherent infeasibility of performing a reduction reaction without a reductant have been presented. Further details on why this reaction is implausible are presented here:
Example 1 states that 1,000 grams of iron slag waste is able to produce 14 grams of hydrogen at 91.7% purity, or 12.8 grams of pure hydrogen. Table 1 reveals that this 1000 grams of slag contains 200 grams of iron, assuming this weight really is the element and not the oxide, which is unlikely; this corresponds to 3.58 moles of iron. If all the iron were present as Fe(0), which it would not be in any combustion product, and it was converted all the way to Fe(III), these 3.58 moles of iron would produce three electrons per iron atom for the reduction of water, or 10.74 moles of electrons. However, forming 12.8 grams of hydrogen requires 12.8 moles of electrons, which we do not have.
Accordingly, it would be difficult for one of ordinary skill in the art to see how the invention functions, and therefore how to properly use the invention.
No assertion in the declaration warrants withdrawal of the prior rejections. Therefore, the rejections are maintained.
Applicant's arguments filed 17 March 2026 have been fully considered but they are not persuasive.
Applicant argues on pages 7-16, through an analysis of the Wands factors, that the disclosure is enabling to one of ordinary skill in the art. However, the arguments presented do not address the critical underlying issue that it should not be possible to create hydrogen from water and carbon dioxide using high-valent iron oxides, as alleged in the specification [0014]. Regardless of the pressure, this reaction is not physically possible, as there is no source of electrons to enable the reduction reaction. The examples in the prior art all use iron metal (e.g., iron filings in Barenbaum) or low-valent iron oxides such as wustite (e.g., US 2017/0217770) to carry out similar reduction reactions. While it is agreed that there is no basis in the law requiring the Applicant to use the same materials as the prior art, as argued on p. 8, one of ordinary skill in the art must understand how to use the invention. As noted above in response to the declaration, there is a gap between the fundamentals of chemistry and the Examples/disclosure as a whole that prevents the claimed invention from being utilized by one of ordinary skill in the art.
The amendments to claim 1 narrow the scope of the claim, but not to the point where the claim is enabled by the specification. The claim still covers a very broad range of compositions for the CCP, and without identifying what the key features of the composition are that enable reduction of water it is still unclear how to enable the invention.
Applicant arguments concerning Mohammadian, p. 9, are also not persuasive because the key feature that is not enabled is the production of hydrogen, which Mohammadian does not address.
Regarding the working examples, p. 9-10, Applicant provides a functional example for only one CCP, iron slag, and given the range of compositions and conditions under which the various CCP of claim 1 are generated, without identifying the key component of the composition one of ordinary skill would not know how to enable the invention for the other compositions of claim 1. Even the CCP of iron slag in Example 1 is problematic in view of the its composition as reported in Table 1 and reasserted in the declaration filed 17 March 2026, and the components as would be understood by one of ordinary skill in the art. Additionally, as noted above in response to the declaration, it is difficult to envision how Example 1 produces so much hydrogen given the composition of the starting materials.
The additional information provided in the declaration shows only how changing pressure affects reaction rate and final pressure, and do not provide further examples of CCPs or the details of the compositions required to enable the invention.
On pages 12-13 Applicant argues that Barenbaum shows that the reaction claimed is possible. However, Barenbaum is explicit about the fact that their method utilizes iron filings, which are not a high-valent iron source; iron filings are comprised of iron metal, would be expected to provide the electrons required to carry out the reduction of water to hydrogen.
Furthermore, while a claim will not be invalidated simply because the embodiments do not contain examples explicitly covering the fill scope of the claim language, the high peculiarity of the claim that hydrogen can be produced from water, carbon dioxide, and high-valent iron oxides requires more evidence covering the full scope of claim 1. In view of the specification there is no unifying feature of the materials recited in claim 1 that one of ordinary skill in the art would recognize as enabling the full scope of the invention.
Applicants assertion that the claim recites a closed, well-defined subset of CCPs is not persuasive: the recited list still covers a very wide range of compositions, as evidenced by Wangs’s finding regarding fly ash alone (Table 2).
Applicant’s arguments that the data reported in Table 1 reference elemental compositions alone and are therefore not ambiguous are also not persuasive, for the reasons detailed above in response to the declaration: it is not physically possible for these ratios to refer only to elements by weight percent of the slag when the slag contains silicon dioxide as the silicon-containing material.
In view of these findings, the conclusion that undue experimentation would be needed to use the invention based on the contents of the disclosure is maintained.
Applicant's arguments with respect to the rejection under 35 USC § 103 have been fully considered but they are not persuasive.
Applicant identifies advantages their invention has over Barenbaum, p. 19-22, including that it sequesters CO2 and utilizes waste products. However, Barenbaum also sequesters CO2, by converting it to hydrocarbons, and Wang teaches that the method can also use fly ash, a waste product. In response to applicant's argument that the references fail to show CO2 uptake by the CCP, it is noted that the features upon which applicant relies are not recited in the rejected claims. Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993).
Applicant further argues, p. 22-24, that the higher pressures used in the instant invention were not disclosed in Barenbaum. While this is true, Barenbaum does teach that pressure is a result effective variable for increasing reaction rate and yield ([0049] and Fig. 2), and therefore the higher pressures instantly claimed are considered an obvious variation of those taught by Barenbaum.
Applicants arguments with respect to Wang and Schure, p. 24-26, do not address how these references are incorporated into the rejection of claim 1. Claim 1 only requires the presences of fly ash, not its role in the reaction that occurs. Because the combination of Wang and Schure would lead one of ordinary skill in the art to including fly ash as a catalyst in the method of Barenbaum, thereby arriving at the limitations of claim 1, the claim is rejected as obvious over the prior art.
Applicant further argues, p. 26-27, that Mohammadian does not remedy the deficiencies of Barenbaum, Wang, and Schure. However, the combination of Barenbaum, Wang, and Schure is not deficient, as analyzed above. Mohammadian is used only as an evidentiary references to show that the pH of the system taught by Barenbaum would lie in the range recited in claim 27.
Applicant’s arguments with respect to Keith, p. 27-28, are also not persuasive because Keith is relied upon for teaching features related to CO2 sequestration, and not hydrogen production, and the features of hydrogen production are taught by the combination of Barenbaum, Wang, and Schure, as detailed above.
Conclusion
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.
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/NICHOLAS A. PIRO/Assistant Examiner, Art Unit 1738
/PAUL A WARTALOWICZ/Primary Examiner, Art Unit 1735
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