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 .
Status of Claims
Herein, claims 14-32 are pending. Claims 14 and 29 are amended and claims 15-28 and 30-32 are as previously presented.
Claim Rejections - 35 USC § 103
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.
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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 14-32 are rejected under 35 U.S.C. 103 as being unpatentable over Fedeyko et al. (U.S. Patent Application No. US-20190224657A1) in view of Gao et al. (Journal of Catalysis 2019, 378, pp. 363-375).
With regard to claim 14, Fedeyko et al. teaches SCR catalyst comprising a CHA-framework zeolite, preferably an SSZ-13 zeolite [0021], with a silica-alumina ratio (SAR) of 10-25 [0010], and with embedded copper ions [0032] and a combination of at least one alkali metal and one alkaline earth metal [0033]. Fedeyko et al. notes that it is desirable to have a high catalytic activity at low temperatures, but to not have an excessively high Cu loading which decreases selectivity of NOx to N2 [0008]. Fedeyko et al. does not teach that the Cu-CHA type zeolite has an SAR of 8.0 or less, as noted above.
However, Gao et al. teaches a Cu-SSZ-13 zeolite (which has a CHA-type framework) with an SAR of 6 which combines high loading capacity of Cu and catalytic activity for NOx SCR with improved hydrothermal stability due to alkali additions (pp. 363, Abstract & pp. 364, left col.). Gao et al. specifically teaches that the copper active site found in CHA-type zeolites with a higher SAR do not contribute to NOx SCR, and in fact catalyze NH3 oxidation instead, and thus lower SAR zeolites are desirable as NOx SCR catalysts (pp. 363, right col., line 7 – pp. 364, left col., line 14). Therefore, a person of ordinary skill in the art would have found it obvious to modify the composition of Fedeyko et al. to replace the taught Cu-CHA type zeolites with SAR between 10-20 with the SAR = 6 Cu-CHA type zeolite taught by Gao et al., which reads to the instantly claimed composition, in order to achieve a higher catalytic activity in the SCR reaction with good hydrothermal stability.
With regard to claim 15, Fedeyko et al. teaches that copper in a Cu-CHA type zeolite, a molar ratio of the transition metal (copper) to framework aluminum is not more than 0.5, and preferably 0.10-0.24 [0035], which is within the instantly claimed range of 0.10-0.40 Cu:Al in the framework. Fedeyko et al. further teaches that high Cu loadings (represented by Cu:Al molar ratios > 0.25) perform worse at high temperatures due to poor N2 selectivity in NOx SCR [0008].
Gao et al. teaches Cu-SSZ-13 (CHA-type) zeolites with a SAR of 6 and a Cu loading of 3 wt% with a Cu to co-cation atomic ratio of 0.1 to 1.0, (pp. 364, right col., lines 49-51). At a 3 wt% Cu loading, the SAR = 6 CHA-framework zeolite has a calculated Cu atoms:Al atoms molar ratio of 0.110 when no co-cation is added, and a maximum of 0.113 when the highest loading of the heaviest co-cation (Ca) is added, which is expected to have the greatest effect on the Cu:Al molar ratio.
Therefore, in applying the Cu-SSZ-13 (CHA-type) zeolites taught by Gao et al. to the composition taught by Fedeyko et al., a person of ordinary skill in the art would have found it obvious, based upon the taught composition of Gao et al. with a Cu:Al molar ratio ranging from 0.110-0.113 in SAR=6 zeolites, the teachings of Fedeyko et al. (<0.5 Cu:Al in SAR 10-20 zeolites), and Fedeyko et al.’s suggestion that there is an ideal range of copper loading to achieve the best NOx SCR performance, to select a Cu:Al molar ratio within the claimed range of 0.10-0.40 for a CHA-framework zeolite with an alkali metal and alkali earth metal co-cation.
With regard to claims 16-18, Fedeyko et al. discloses samples 3a with a Ca:Al molar ratio of 0.14 (see Table 1), which is within the claimed range of 0.01≤x≤0.20 for an alkaline earth metal.
Fedeyko et al. does not provide a worked example of molar ratios of an alkali metal and alkaline earth metal with respect to aluminum where both are used in combination. However, it does teach that the combined amount of transition metal, alkali metal, and alkaline earth metal should be in a molar ratio of <0.6 with respect to aluminum [0036]. Using the preferred ratio of Cu:Al, the total ratio of alkali metal and alkaline earth metal (Am) to aluminum is ≤0.30-0.35 Am:Al. The two components, the alkali metal and alkaline earth metal, therefore would each have a molar ratio of between 0<x≤0.30-0.35 with respect to aluminum. These expected ratios of alkali metal to aluminum and alkaline earth metal to aluminum overlap the instantly claimed ranges of 0.005≤x≤0.10 for an alkali metal and 0.01≤x≤0.20 for an alkaline earth metal. With respect to the encompassing and overlapping ranges previously discussed, the subject matter as a whole would have been obvious to one of ordinary skill in the art at the time of invention to select the portion of the prior art’s range which is within the range of the applicants’ claims because it has been held prima facie case of obviousness to select a value in a known range by optimization for the results. In re Aller, 105 USPQ 233. Additionally, the subject matter as a whole would have been obvious to one of ordinary skill in the art at the time invention was made to have selected the overlapping portion of the range disclosed by the reference because overlapping ranges have been held to be a prima facie case of obviousness. In re Malagari, 182 USPQ.
With regard to claim 19, Fedeyko et al. teaches a Cu-doped CHA-type zeolite with a Cu:Al molar ratio of preferably 0.10-0.24, and approximate ratios of 0<x≤0.30-0.35 alkali metal to aluminum and alkaline earth metal to aluminum. As discussed with regard to claims 16-18, it would have been obvious to one of ordinary skill in the art to select the overlapping portion of the instantly claimed range and range taught by Fedeyko et al. through process optimization.
In regard to claim 22, Fedeyko et al. teaches that the alkali metal dopant may be sodium or potassium, or a combination thereof.
In regard to claim 23, Fedeyko et al. teaches that the alkaline earth metal dopant may be barium, calcium, or a combination thereof.
In regard to claim 24, Fedeyko et al. teaches that the alkali metal and alkaline earth metal-doped Cu/CHA-type zeolite is an effective SCR catalyst ([0010]).
In regard to claim 26, Fedeyko et al. teaches that the catalyst composition may be deposited onto a substrate ([0048]), especially honeycomb geometry substrates ([0049]) in the form of a wash coat layer ([0047]) which anticipates the instantly claimed device comprising a substrate and catalyst layer composed of the composition claimed in claim 14.
In regard to claim 25, Fedeyko et al. teaches that the alkali metal and alkaline earth metal-doped Cu/CHA-type zeolite is an effective SCR catalyst ([0010]).
In regard to claims 27 and 28, Fedeyko et al. teaches that the catalyst composition may be deposited onto a substrate ([0048]), especially honeycomb geometry substrates ([0049]) in the form of a wash coat layer ([0047]).
In regard to claim 29, Fedeyko et al. teach in Example 2 that the CHA-type zeolite powder first underwent ion exchange with copper to form a Cu/CHA-type zeolite and then subsequently underwent ion exchange with a calcium source to yield a Ca,Cu/CHA-type zeolite. The co-doped CHA-zeolite was further aged and then calcined (fired) at 800°C for 16 hours [0073]. As referenced in Example (1a), the ion exchange process involves creating a mixture of the zeolite and the salt for ion exchange in an aqueous environment [0063].
Fedeyko et al. teaches that the extra-framework metals (copper, alkali metal, and alkaline earth metal) may be added to the parent CHA-type zeolite in any order and by any well-known technique such as ion exchange, impregnation, or isomorphous substitution [0039]. From the disclosed details of synthesis, a person of ordinary skill in the art would have inferred that a copper source, an alkali metal source, and an alkaline earth metal source could be added to the parent CHA-type zeolite in one step or in sequence to yield the co-doped zeolite as suggested. The addition of the co-dopants to the parent CHA-type zeolite could be accomplished in a finite number of ways when completed in sequence, and one of ordinary skill in the art. Fedeyko et al. suggested in Examples 2(a-b) that the order in which the co-dopants are added may affect the final composition (pp. 8). Based on the teachings of Fedeyko et al., it would have been obvious to one of ordinary skill to try the instantly claimed steps of first adding a copper source to a CHA-type zeolite, followed by a second step where both the alkali metal source and alkaline earth metal source were added to the Cu/CHA-type zeolite. It has been found that a prima facie case of obviousness exists when there are a finite number of identified predictable solutions which are within the technical grasp of a person of ordinary skill to try. In re KSR, 82 USPQ. See also MPEP 2143.IE.
In regard to claim 30, Fedeyko et al. discloses in Examples 1(a-g) and 2(a-b) that the alkali metal source may be a nitrate salt of the alkali metal ion (see pp. 11-12). For example, Example 1d utilizes sodium nitrate as a starting material [0066].
In regard to claim 31, Fedeyko et al. discloses in Examples 1(a-g) and 2(a-b) that the alkaline earth metal source may be an acetate salt of the alkali metal ion (see pp. 7-8). For example, calcium acetate is used as a starting material in Examples 1a and 2a [0063] & [0073].
In regard to claim 32, as discussed above with respect to claims 30 and 31, Fedeyko et al. discloses both that the alkali metal source is a nitrate salt (sodium nitrate, Example 1d) and that the alkaline earth metal source is an acetate salt (calcium acetate, Examples 1a & 2a).
Response to Arguments
Applicant's arguments filed 07/29/2026 have been fully considered but they are not persuasive.
With regard to claims 14-15, 22-24, & 26 rejected under 35 USC 102(a)(1) over Fedeyko et al., claims 16-19 & 29-32 rejected under 35 USC 103 in view of Fedeyko et al., and claims 20-21, 25, & 27-28 under 35 USC 103 over Fedeyko et al. in view of Gao et al, applicant argues that Fedeyko et al. does not teach an exhaust gas purification catalyst comprising a Cu-CHA type zeolite wherein the Cu-CHA type zeolite has a silica:alumina ratio (SAR) of 8.0 or less as per the amended claims 14 and 29, and thus the claims are not anticipated (Applicant Remarks, pp. 6). The examiner acknowledges this argument, and the rejections made under 35 USC 102(a)(1) have been withdrawn.
Applicant further argues that the claims as amended would not have been rendered obvious by the combination of Fedeyko et al. and Gao et al. (Applicant Remarks, pp. 6). The examiner respectfully disagrees with this characterization of the references. Gao et al. teaches a Cu-CHA type zeolite (SSZ-13 zeolite, with a CHA-framework) with a SAR of 6, which is within the instantly claimed range of 8.0 or less. In light of the change in scope of amended claim 14, new rejections of claims 14-15, 22-24, and 26 have been made under 35 USC 103 over Fedeyko et al. in view of Gao et al. See above rejections for a detailed explanation of obviousness.
Further with regard to the rejection of claims 14-15, 22-24, and 26 applicant argues that the newly amended range of SAR in claim 14, i.e. 8.0 or lower, produces unexpected results with respect to the reduction in N2O formation achieved by incorporating alkali metals and alkaline earth metals into Cu-CHA having an SAR of 8 or less. Applicant argues that Fedeyko et al. does not contemplate the effect of alkali metal and alkali earth metal additions in a Cu-CHA type zeolite with a SAR of 8.0 or lower on lessening N2O formation during NOx SCR (Applicant Remarks, pp. 7). Applicant further argues that Gao et al. does not cure such deficiencies in Fedeyko et al., and as such any combination of Fedeyko et al. and Gao et al. would not render the limitations of the amended claims obvious (Applicant Remarks, pp. 8).
In response to applicant's argument that Fedeyko et al. does not contemplate the effect of alkali and alkali earth metal additions of N2O selectivity in NOx SCR, the examiner respectfully disagrees. In Figure 5 of Fedeyko et al., it is clearly demonstrated that at operating temperatures above 450°C, a 2 wt% loading of Ca as a co-cation decreases the amount of N2O (ppm) produced as compared to no Ca loading and 1 wt% loading. Fedeyko et al. discusses such in [0090]. Furthermore, the fact that the inventor has recognized another advantage which would flow naturally from following the suggestion of the prior art cannot be the basis for patentability when the differences would otherwise be obvious. See Ex parte Obiaya, 227 USPQ 58, 60 (Bd. Pat. App. & Inter. 1985).
In response to applicant’s argument that Gao et al. does no cure the deficiencies of Fedeyko et al. with regard to the argued unexpected results of co-cation addition, the examiner respectfully disagrees with the notion on the grounds that Fedeyko et al. teaches an effect of alkali earth metal loading on N2O production during NOx SCR and the combination of Fedeyko et al. and Gao et al. yields a Cu-CHA type zeolite with a SAR of 8.0 or less (in the instant case, 6) with an alkali and alkali earth metal as co-cations.
Therefore, after full consideration of applicant’s arguments, they are considered not persuasive.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
Gao et al. Understanding ammonia selective catalytic reduction kinetics over Cu/SSZ-13 from motion of the Cu ion. Journal of Catalysis 2014, 319, pp. 1-14.
Gao et al. Effects of Si/Al ratio on Cu/SSZ-13 NH3-SCR catalysts: Implications for the active Cu species and the roles of Bronsted acidity. Journal of Catalysis, 2015, 31, pp. 25-38.
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 MORDECAI M LEAVITT whose telephone number is (571)272-6637. The examiner can normally be reached Monday-Friday 8AM-5PM.
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/MORDECAI M LEAVITT/Examiner, Art Unit 1742 /CHRISTINA A JOHNSON/Supervisory Patent Examiner, Art Unit 1742
