UNITED STATES PATENT AND TRADEMARK OFFICE
`
`______________________________________________________________
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`______________________________________________________________
`
`JOHNSON MATTHEY INC., and JOHNSON MATTHEY PLC,
`
`Petitioners,
`
`v.
`
`BASF CORPORATION,
`
`Patent Owner
`
`______________________________________________________________
`
`Case IPR2015-01266
`
`Patent 9,039,982
`______________________________________________________________
`
`PATENT OWNER’S RESPONSE TO PETITION FOR INTER PARTES
`REVIEW OF U.S. PATENT NO. 9,039,982 PURSUANT TO 37 CFR § 42.120
`
`
`
`
`
`

`
`TABLE OF CONTENTS
`
`Page
`
`TABLE OF AUTHORITIES ................................................................................... iii 
`
`PATENT OWNER’S TABLE OF EXHIBITS ......................................................... iv 
`
`I. 
`
`II. 
`
`INTRODUCTION ........................................................................................... 1 
`
`THE TECHNOLOGICAL CONTEXT FOR THE ’982 PATENT ................ 6 
`
`A. 
`
`The State Of The Art In 2003 ................................................................ 6 
`
`1. 
`
`The State Of The Art Of Soot After Treatment .......................... 8 
`
`2. 
`
`The State Of The Art Of NOx After Treatment ........................ 13 
`The Person Of Ordinary Skill .............................................................. 16 
`
`B. 
`
`III.  OVERVIEW OF THE ’982 PATENT .......................................................... 19 
`
`IV.  ARGUMENT ................................................................................................. 20 
`
`A. 
`
`The Skilled Artisan Would Not Have Been Motivated To
`Washcoat A Soot Filter With An SCR Catalyst And Would Not
`Have Had A Reasonable Expectation Of Success .............................. 20 
`
`1. 
`
`2. 
`
`3. 
`
`The Skilled Artisan Would Have Been Concerned About
`An Inability To Recycle NO2 In The Soot Filter ...................... 21 
`The Skilled Artisan Would Have Been Concerned About
`Poor Soot Oxidation And Poor NOx Conversion Due To
`NH3 Oxidation ........................................................................... 23 
`The Skilled Artisan Would Not Have Had A Reasonable
`Expectation Of Success In Using A Zeolite Catalyst In
`The Thermal Environment Of A Soot Filter And Would
`Not Have Been Motivated To Do So ........................................ 27 
`
`i
`
`
`
`

`
`4. 
`
`The Skilled Artisan Would Have Been Concerned About
`Negative
`Interaction
`Between
`Exhaust/Unburnt
`Hydrocarbons And The SCR Catalyst ...................................... 32 
`
`Hüthwohl Does Not Provide A Reasonable Expectation Of
`Success ................................................................................................ 33 
`
`In The 2003 Time Frame Industry Pursued Options Different
`From Applying An SCR Catalyst Washcoat To A Soot Filter ........... 38 
`
`The Prospect Of Saving Space Would Not Have Motivated The
`Skilled Artisan To Washcoat A Soot Filter With An SCR
`Catalyst ................................................................................................ 43 
`
`Hashimoto Does Not Establish A Reasonable Expectation Of
`Success And There Is No Motivation To Combine Hashimoto
`With Hüthwohl .................................................................................... 45 
`
`Teraoka Does Not Establish A Reasonable Expectation Of
`Success ................................................................................................ 48 
`
`Secondary Considerations Confirm That The ’982 Patent Is
`Nonobvious ......................................................................................... 50 
`
`1. 
`
`2. 
`
`3. 
`
`Long Felt Need For The Claimed Invention After
`Announcement Of The EU Emissions Standards
`Demonstrates Nonobviousness ................................................. 50 
`
`Skepticism For The Approach Followed In The ’982
`Patent Demonstrates Nonobviousness ...................................... 52 
`
`Industry Praise For The Claimed Invention Demonstrates
`Nonobviousness ........................................................................ 54 
`
`There Is No Evidence That Others Achieved The Invention
`Claimed In The ’982 Patent ................................................................ 56 
`
`The Petition Is Deficient With Respect To Claim 15 ......................... 58 
`
`Dr. Tennent’s Testimony Is Entitled To No Weight ........................... 59 
`
`B. 
`
`C. 
`
`D. 
`
`E. 
`
`F. 
`
`G. 
`
`H. 
`
`I. 
`
`J. 
`
`CONCLUSION .............................................................................................. 60 
`ii
`
`V. 
`
`
`
`

`
`
`
`TABLE OF AUTHORITIES
`
`Page(s)
`
`Cases 
`In re Hedges,
`783 F.2d 1038 (Fed. Cir. 1986) .......................................................................... 48
`
`Otsuka Pharm. Co. v. Sandoz, Inc.,
`678 F.3d 1280 (Fed. Cir. 2012) .......................................................................... 32
`
`Procter & Gamble Co. v. Teva Pharm. USA, Inc.,
`566 F.3d 989 (Fed. Cir. 2009) ............................................................................ 38
`
`Rambus Inc. v. Rea,
`731 F.3d 1248 (Fed. Cir. 2013) .......................................................................... 50
`
`Sanofi-Synthelabo v. Apotex, Inc.,
`550 F.3d 1075 (Fed. Cir. 2008) .......................................................................... 26
`
`Abbott Labs. v. Sandoz, Inc.,
`544 F.3d 1341 (Fed. Cir. 2008) .......................................................................... 38
`
`Stratoflex, Inc. v. Aeroquip Corp.,
`713 F.2d 1530 (Fed. Cir. 1983) .......................................................................... 50
`
`Statutes 
`
`37 C.F.R. § 42.65(a) ................................................................................................. 60
`
`iii
`
`
`
`
`
`
`
`

`
`PATENT OWNER’S TABLE OF EXHIBITS
`
`August 13, 2013, Right of Appeal Notice (RAN), Reexamination
`Control Number 95/001,745
`
`October 30, 2014, Right of Appeal Notice (RAN),
`Reexamination Control Number 95/001,744
`
`September 7, 2011, Request for Inter Partes Reexamination,
`(U.S.P.N. 7,229,597, Reexam Control No. 95/001,745)
`
`March 9, 2012 , Third Party Comments,  
`(U.S.P.N. 7,229,597, Reexam Control No. 95/001,745)
`
`November 15, 2012, Third Party Comments,  
`(U.S.P.N. 7,229,597, Reexam Control No. 95/001,745)
`
`May 3, 2012, Action Closing Prosecution, 
`(U.S.P.N. 7,902,107, Reexam Control No. 95/001,744)
`
`May 14, 2014, Action Closing Prosecution,  
`(U.S.P.N. 7,902,107, Reexam Control No. 95/001,744)
`
`EPA’s Climate Change, Understanding Global Warming
`Potentials
`
`Todd Ballinger et al., Evaluation of SCR Catalyst Technology on
`Diesel Particulate Filters, SAE International Journal of Fuels and
`Lubricants, Vol. 2, Issue 1, 2009.
`
`Mojghan Naseri et al., Development of SCR on Diesel Particulate
`Filter System for Heavy Duty Applications, SAE International
`Journal of Engines, Vol. 4, Issue 1, April 12, 2011.
`
`Soo-Youl Park et al., A Model Development for Evaluating Soot-
`NOx Interactions in a Blended 2-Way Diesel Particulate
`Filter/Selective Catalytic Reduction, I&EC Research, 2012.
`
`
`
`Exhibit 2001
`
`Exhibit 2002
`
`Exhibit 2003
`
`Exhibit 2004
`
`Exhibit 2005
`
`Exhibit 2006
`
`Exhibit 2007
`
`Exhibit 2008
`
`Exhibit 2009
`
`Exhibit 2010
`
`Exhibit 2011
`
`Exhibit 2012
`
`Prosecution History for U.S.P.N. 8,899,023
`
`
`
`iv
`
`

`
`Exhibit 2013
`
`Exhibit 2014
`
`Exhibit 2015
`
`Exhibit 2016
`
`Exhibit 2017
`
`Exhibit 2018
`
`Exhibit 2019
`
`Exhibit 2020
`
`Exhibit 2021
`
`Exhibit 2022
`
`Exhibit 2023
`
`Exhibit 2024
`
`Exhibit 2025
`
`Exhibit 2026
`
`
`
`Biography of Derek C. Walter
`
`Biography of Michael P. Harold, University of Houston.
`
`DieselNet.com, Diesel Filter Systems: Catalyzed Diesel Filters
`Technology Guide
`
`Claus Görsmann, et al., Catalytic Coatings for Active and Passive
`Diesel Particulate Filter Regeneration, Chemical Monthly, 2004.
`
`Mona Meisami-Azad, et al., PCA-based Linear Parameter
`Varying Control of SCR Aftertreatment Systems, 2011 American
`Control Conference, 2011.
`
`M. Shelef & R.W. McCabe, Twenty-five years after introduction
`of automotive catalysts: what next?, Catalysis Today, 2000.
`
`Andrew P. Walker, et al., The Development and Performance of
`the Compact SCR-Trap Systems: A 4-Way Diesel Emission
`Control Systems, Diesel Exhaust Emissions Control, 2003.
`
`Isabelle Melscoet-Chauvel, et al., High Porosity Cordierite Filter
`Development for Nox/PM Reduction, Developments in Advanced
`Ceramics and Composites, 2005.
`
`DieselNet.com, What’s New: Johnson Matthey introduces
`integrated SCRT system for stationary engines
`
`Yang Zheng, Effects of CO, H2 and C3H6 on Cu-SSZ-13
`catalyzed NH3-SCR, Catalysis Today, 2015.
`
`U.S. Patent No. 7,648,548 to Miao
`
`S.B. Ogunwumi, et al., Aluminum Titanate Compositions for
`Diesel Particulate Filters, Diesel Exhaust Emission Control 2005,
`2005.
`
`Transcript of Deposition of Michael P. Harold , February 9, 2016
`
`Transcript of Deposition of David L. Tennent, February 16, 2016
`
`v
`
`

`
`Exhibit 2027
`
`Exhibit 2028
`
`Exhibit 2029
`
`Exhibit 2030
`
`Exhibit 2031
`
`Exhibit 2032
`
`Exhibit 2033
`
`Exhibit 2034
`
`Exhibit 2035
`
`Exhibit 2036
`
`
`
`Philip G. Blakeman, et al. Developments in Diesel Emission
`Aftertreatment Technology, Society of Automotive Engineers,
`2003.
`
`Timothy V. Johnson, Diesel Emission Control: 2001 in Review,
`Diesel Exhaust Emissions Control 2002: SCR, HC, DeNOx, and
`Measurement, 2002.
`
`K.V.R. Babu, et al., The Effect of Nox/Soot Ratio on the
`Regeneration Behaviour of Catalysed Diesel Particulate Filters
`for Heavy Duty Applications, Society of Automotive Engineers,
`2005.
`
`Kenneth G. Rappé, Integrated Selective Catalytic Reductions—
`Diesel Particulate Filter Aftertreatment: Insights into Pressure
`Drop, NOx Conversion, and Passive Soot Oxidation Behavior,
`I&EC Research, 2014.
`
`Pranit S. Metkar, et al., Experimental study of mass transfer
`limitations in Fe- and Cu-Zeolite-based NH3-SCR monolithic
`catalysts, Chemical Engineering Science, 2011.
`
`Giovanni Cavataio, et al., Cu/Zeolite SCR on High Porosity
`Filters: Laboratory and Engine Performance Evaluations, SAE
`International, 2009.0
`
`Jong H. Lee, et al., Evaluation of Cu-Based SCR/DPF
`Technology for Diesel Exhaust Emission Control, SAE
`International, 2008.
`
`Guy R. Chandler, et al., An Integrated SCR and Continuously
`Regenerating Trap System to Meet Future Nox and PM
`Legislation, Diesel Exhaust Aftertreatment, 2000.
`
`J. Gieshoff, et al., Regeneration of Catalytic Diesel Particulate
`Filters, Diesel Exhaust Emission Control: Diesel Particulate
`Filters, 2001.
`
`Yinyan Huang, et al., Deactivation of Cu/Zeolite SCR Catalyst
`Due to Reductive Hydrothermal Aging, SAE International, 2008.
`
`vi
`
`

`
`Exhibit 2037
`
`Exhibit 2038
`
`Exhibit 2039
`
`Exhibit 2040
`
`Exhibit 2041
`
`Exhibit 2042
`
`Exhibit 2043
`
`Exhibit 2044
`
`Chapter 6 from Ronald M. Heck, et al. “Catalytic Air Pollution
`Control” (2002)
`
`David Jollie, “Platinum 2009,” Johnson Matthey, 2009.
`
`Y. Miyairi, et al., Numerical Study on Forced Regeneration of
`Wall-flow Diesel Particulate Filters, Diesel Exhaust Emission
`Control: Diesel Particulate Filters, 2001.
`
`Gabriele Centi & Siglinda Perathoner, Nature of active species in
`copper-based catalysts and their chemistry of transformation of
`nitrogen oxides, Applied Catalysis, 1995.
`
`Katariina Rahkamaa-Tolonen, et al., The effect of NO2 on the
`activity of fresh and aged zeolite catalysts in the NH3-SCR
`reaction, Catalysis Today, 2005.
`
`Joo-Hyoung Park, et al., Hydrothermal stability of CuZSM5
`catalyst in reducing NO by NH3 for the urea selective catalytic
`reduction process, Journal of Catalysis, 2006.
`
`W.E.J. van Kooten, et al., Deactivation of zeolite catalysts used
`for NOx removal, Applied Catalysis, 1999.
`Gongshin Qi, et al., Deactivation of La-Fe-ZSM-5 catalyst for
`selective catalytic reduction of NO with NH3: field study results,
`Applied Catalysis, 2004.
`
`Exhibit 2045
`
`Expert Report of Mark Crocker
`
`
`
`vii
`
`

`
`I.
`
`INTRODUCTION
`U.S. Patent No. 9,039,982 (“the ’982 patent”)1 is directed to a novel catalytic
`
`article consisting of a high porosity soot filter2 coated with a metal promoted
`
`zeolite catalyst. This combination provided a compact means for simultaneously
`
`limiting both particulate matter (“PM”) and nitrogen oxide (“NOx”) emissions from
`
`diesel exhaust, thus allowing the auto and truck industries to meet strict emissions
`
`standards that had been implemented around the world from the 1990s onwards.
`
`As Patent Owner explained in its Preliminary Response, Petitioner’s obviousness
`
`case requires four unrelated references, none of which come close to the claimed
`
`
`1 Petitioner has filed IPR petitions challenging the claims of U.S. Patent Nos.
`
`8,889,023, 9,032,709, and 9,039,982, all of which share the same specification.
`
`See IPR Nos. 2015-01265, 1266, 1267. To assist the Board, Patent Owner notes
`
`that its responses in all of three of these IPRs present the same arguments and are
`
`identical outside of non-substantive differences.
`
`2 The term “soot filter” is often used interchangeably in the art with the terms
`
`particulate filter, particle filter, wall flow monolith, wall flow filter, PM device,
`
`diesel particulate filter, and/or DPF. Herein, Patent Owner has endeavored to
`
`consistently use the term “soot filter,” although the alternative terminology
`
`sometimes appears in the context of discussing specific references.
`
`
`
`1
`
`

`
`invention. In its institution decision, the Board did not disagree with this basic
`
`point. Nevertheless, based on the limited record at the institution stage, the Board
`
`found Petitioner’s explanation for why the skilled artisan would have combined
`
`Petitioner’s four references to be reasonable. Paper No. 8 at 19-20.
`
`The Board’s analysis, however, was brief, and focused on the disclosure in
`
`the Hashimoto reference of soot filters with pore size and porosity values
`
`corresponding to the ranges recited in the claims. Id. at 20. The developed record
`
`demonstrates that filter porosity is only a small part of the story. In 2003, it was
`
`routine and commonplace to coat a soot filter with an oxidation catalyst. But the
`
`Board did not consider the extensive evidence demonstrating the numerous reasons
`
`why the skilled artisan would not have coated such a filter with a reduction
`
`catalyst, as required by all claims of the ’982 patent. The decision by the inventors
`
`to coat a soot filter with a reduction catalyst and use it for treating diesel exhaust
`
`was contrary to several lines of conventional wisdom in the field.
`
`In 2003, it was well-known that there is synergy when a soot filter is coated
`
`with an oxidation catalyst because the catalytic material necessary for oxidizing
`
`soot is brought in direct contact with the soot in a highly oxidizing environment.
`
`The conventional wisdom, however, was that this synergy would vanish if one
`
`tried to reduce NOx on the filter by instead coating it with a reduction catalyst. In
`
`2003, the industry believed that NO2 was critical as an oxidant for combustion of
`2
`
`
`
`

`
`soot on the filter. Indeed, the most widely used method in the industry for
`
`controlling soot required an oxidation catalyst upstream of the filter so that the
`
`NO2 could be generated for use on the soot filter. The skilled artisan would not
`
`have coated a soot filter with a reduction catalyst because a reduction catalyst
`
`would consume the NO2 that had been deemed so precious for soot combustion.
`
`This would have been viewed as sabotaging the effectiveness of the soot filter.
`
`Even if this were not a barrier, coating a soot filter with a reduction catalyst
`
`requires a catalyst that can withstand the high temperatures encountered during
`
`normal use of a soot filter. Petitioner contends that Speronello teaches that metal
`
`zeolite catalyst have this property, and that such catalysts were “the best” option
`
`for use on a soot filter. The Speronello reference, however, teaches that its
`
`catalysts are stable only up to 600ºC, hundreds of degrees lower than the
`
`temperatures that can be experienced by a soot filter.
`
`As to the Hashimoto reference, although it discloses high porosity filters, it
`
`does not address the delicate balance between thermal stability of the filter and
`
`filter porosity. This remained a great challenge as late as 2005. In 2003, the
`
`conventional wisdom was that maintaining filter integrity during the extreme
`
`temperatures of filter regeneration required high thermal mass. The decision to
`
`employ a high porosity filter with a lower thermal mass was yet another example
`
`of how the ’982 patent inventors proceeded contrary to conventional wisdom.
`3
`
`
`
`

`
`Citing Hüthwohl, the Board nevertheless stated that there was motivation in
`
`the industry to coat a soot filter with a reduction catalyst. Development of the
`
`record, however, shows that this was not so. Although Hüthwohl discloses a soot
`
`filter impregnated with some unstated reduction catalyst, it provides no
`
`information regarding the performance of this filter, a point confirmed by
`
`Petitioner’s expert. Rather, Hüthwohl contemplates a mandatory downstream
`
`reduction catalyst on a flow-through substrate that has no soot filtering capability.
`
`All data is based on the use of this downstream reduction catalyst. Petitioner’s
`
`expert acknowledged that based on the information in Hüthwohl, one cannot rule
`
`out the possibility that no NOx reduction is taking place on Hüthwohl’s soot filter.
`
`Hüthwohl thus cannot establish a reasonable expectation of being able to overcome
`
`the numerous issues described above, which would have dissuaded the skilled
`
`artisan from coating a soot filter with a reduction catalyst.
`
`It is instructive to compare Petitioner’s positions in this matter to what was
`
`actually taking place in 2003 based on record evidence. According to Petitioner’s
`
`expert, the “industry would have followed the teachings of Huethwohl.” Ex. 1004
`
`¶ 35. He asserts that the entire industry believed by 2002 that meeting emissions
`
`standards “required” putting a high amount of a reduction catalyst washcoat onto a
`
`high porosity filter. Id. ¶ 26. Yet, there is no prior art that discloses or suggests
`
`this combination, a point that Petitioner’s experts confirmed on cross. See Ex.
`4
`
`
`
`

`
`2026 [Tennent Tr.] at 104:4-8; Ex. 2025 [Harold Tr.] at 152:24-153:6.
`
`The failure of the prior art to teach this key aspect of the ’982 patent cannot
`
`be
`
`ignored, particularly when one considers
`
`the evidence of secondary
`
`considerations submitted by Patent Owner. In the 1990s governments imposed
`
`strict new emissions standards on not just particulate matter, but also NOx. The
`
`entire industry faced legislative and regulatory deadlines due to these newly passed
`
`emissions standards. Petitioner acknowledges that there were no “pre-existing
`
`answers for complying” with the new standards and that this presented a “huge
`
`challenge” for the industry. Petition at 22-23. Petitioner’s expert testified that it
`
`was a “huge problem.” Ex. 2026 [Tennent Tr.] at 36:24. “If you came up with a
`
`solution to this problem, you would have the potential for a very large market,
`
`millions of cars, all the heavy-duty trucks.” Id. at 37:1-4.
`
`Nevertheless, the solution provided by the ’982 patent did not promptly
`
`appear. In fact, the industry pursued numerous alternative directions, and it was
`
`not until years after BASF filed its patents that the industry began to publish
`
`reports regarding the use of high porosity soot filters coated with reduction
`
`catalysts. These reports described the approach as “new technology,” and
`
`expressed caution regarding its potential pitfalls. As documented below, it is only
`
`through the use of hindsight that Petitioner now contends that the ’982 patent is
`
`obvious. This reasoning should be rejected, and the’982 patent should be affirmed.
`5
`
`
`
`

`
`II. THE TECHNOLOGICAL CONTEXT FOR THE ’982 PATENT
`Whether the ’982 patent is obvious can only be evaluated with a proper
`
`understanding of the relevant technological context in the 2003 time frame,
`
`including the state of the art and the competencies of the skilled artisan. Evaluating
`
`the ’982 patent within this context reveals that it was advanced for its time and that
`
`it represented thinking contrary to the conventional wisdom in the field.
`
`A. The State Of The Art In 2003
`The ’982 patent pertains to a catalyst article for the treatment of diesel
`
`exhaust. “Diesel engine exhaust is a heterogeneous mixture which contains not
`
`only gaseous emissions such as carbon monoxide (‘CO’), unburned hydrocarbons
`
`(‘HC’) and nitrogen oxides (‘NOx’), but also condensed phase materials (liquids
`
`and solids) which constitute the so-called particulates or particulate matter.” Ex.
`
`1001 at 1:25-30. Diesel engines are considered to be “lean-burn” engines,
`
`meaning that they operate in an environment with an excess of oxygen that is
`
`highly oxidizing. See Ex. 1011 at 186 (“Diesels operate very lean of
`
`stoichiometric, with air:fuel ratios greater than about 22.”). The lean environment
`
`of diesel exhaust had long been known to present complications for reducing NOx
`
`emissions. Id. at 204 (“The catalytic reduction of NOx from lean-burn diesel
`
`engines has proved to be an even greater challenge relative to the stoichiometric
`
`operated gasoline engine. The modern [three-way] catalyst cannot reduce NOx in
`6
`
`
`
`

`
`the presence of excess O2.”) (citation omitted).
`
`As acknowledged in the Petition, following the enactment of stricter
`
`emissions standards, the industry faced a “huge challenge.” There were “no pre-
`
`existing” solutions to the problem of simultaneously reducing NOx and particulate
`
`matter emissions. Petition at 22-23. As of 2003, the conventional wisdom was
`
`that there was a tradeoff between reducing NOx emissions and reducing particulate
`
`matter. The Heck reference, which is a standard authority in the field, described
`
`this “NOx -particulate tradeoff” as follows:
`
`The control of particulate emissions and NOx represent significant
`challenges to the diesel engine manufacturer because they are coupled
`inversely. When the engine operates cooler, it produces less NOx but
`more particulate. At higher temperatures combustion is more
`complete, generating less particulate but more NOx. This is referred
`to as the NOx -particulate tradeoff; when one is high the other is low.
`
`Ex. 1011 at 191 (emphasis in original); see also Ex. 2025 [Harold Tr.] at 141:19-
`
`142:2 (“Well, the challenge with achieving both at the same time is there’s a
`
`standard NOx-soot tradeoff.”)
`
`Thus, as of 2003, the conventional wisdom was that a divide-and-conquer
`
`approach would be necessary: one could tune the engine to produce less NOx, and
`
`then deal with soot through exhaust after treatment. Alternatively, one could tune
`
`the engine to produce less soot, and then deal with NOx through exhaust after
`7
`
`
`
`

`
`treatment. See, e.g., Ex. 2027 ¶¶ 24, 43 (hereinafter “Crocker Decl.”). The
`
`following 2003 publication by Petitioner’s researchers is exemplary of this
`
`thinking:
`
`In principle there are two ways to meet the Stage 4 limits. [Exhaust
`gas recycle] may be applied to reduce the NOx level, but this will lead
`to an increase in PM emissions, so it is expected that a filter will need
`to be added to control PM emissions when using this strategy. The
`alternative approach is to advance the injection timing, which leads to
`low PM emissions (within the Stage 4 limits) but high NOx emissions
`(outside the Stage 4 limits). Selective Catalytic Reduction (SCR) will
`then be applied to control the NOx (see below).
`
`Ex. 2027.007. Below, the state of the art for treating both soot and NOx
`
`individually is described. The techniques discussed below are what the skilled
`
`artisan would have used in connection with a divide-and-conquer strategy based on
`
`the “NOx -particulate tradeoff.”
`
`The State Of The Art Of Soot After Treatment
`
`1.
`In 2003, the primary after treatment technique for dealing with particulate
`
`matter was the use of a soot filter to physically trap soot. In its institution decision,
`
`the Board described the structure of the soot filter. See Paper No. 8 at 3-5.
`
`Beginning in the late ‘80s, the industry augmented the soot filter with an upstream
`
`oxidation catalyst that would oxidize NO in the exhaust to NO2, the latter of which
`
`was known to be a potent oxidizing agent for the oxidation of soot. See, e.g., Ex.
`8
`
`
`
`

`
`2025 [Harold Tr.] at 54:23-55:4 (“Q. What are the most important oxidizing agents
`
`during passive filter regeneration? A. Well, I can list the oxidants that participate.
`
`One is O2 molecular oxygen. The other would be NO2, nitrogen dioxide. I think
`
`nitrogen dioxide is known to be a more potent oxidant than molecular oxygen.”);
`
`id. at 31:3-16 (“Generally speaking, there’s very little NO2 coming out of an
`
`engine. So one role of the diesel oxidation catalyst is to oxidize certainly
`
`hydrocarbons and carbon monoxide, but also to convert NO to NO2 because the
`
`NO2 is beneficial downstream in the system. Q. And that’s something that was
`
`understood as of 2003? A. Well, I think what was understood in the literature is
`
`the beneficial effect of NO2, for example, on soot oxidation, as one example. Q.
`
`Okay. And that was true as of 2003? A. Yes.”); Crocker Decl. ¶¶ 26-28.
`
`
`
`This approach of including an oxidation catalyst upstream of the soot filter
`
`was commercialized by Petitioner Johnson Matthey, Inc. (“JMI”) under the
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`tradename CRT®. See, generally e.g., Ex. 2016.007-008. As the Petitioner states,
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`as of 2003, this approach of utilizing NO2 for the oxidation of soot in a filter
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`“provided the ‘most successful approach to date’ and had been commercialized
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`‘throughout the world,’ including in Europe, the United States, and Japan.”
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`Petition at 9.
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`Subsequent to the CRT®, the industry began integrating the oxidation
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`catalyst directly into the soot filter by coating it with the oxidation catalyst. See
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`Crocker Decl. ¶¶ 29-32. The coated filter operated on a principle similar to the
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`CRT®, but allowed for more efficient use of NO2. Id. ¶ 32. Indeed, after a
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`molecule of NO2 is converted to NO through the oxidation a hydrocarbon
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`molecule, it can be reconverted to NO2 by the oxidation catalyst and reused for the
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`oxidation of more soot while it is still passing through the filter. See, e.g., Ex.
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`2016.009 (“Over the catalytic coating of the filter NO can be re-oxidised to NO2 by
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`present oxygen, and is therefore available for further soot oxidation.”).
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`Thus, as of 2003, the skilled artisan understood that there was a synergy
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`between the use of an oxidation catalyst and a soot filter. See Crocker Decl. ¶¶ 28.
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`In particular, the skilled artisan would have been interested in using NO2 for soot
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`oxidation on the filter and would have viewed this as critical. See id. ¶¶ 32, 43; Ex.
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`2025 [Harold Tr.] at 98:12-15 (“So that the combination of a catalyst, the presence
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`of NO2, which reduces the oxidation temperature, those are both key to the
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`continuous regeneration to occur.”); id. at 102:21-24 (“So definitely in the ‘90s the
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`community would have known that NO2 was an integral part of an oxidant to help
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`in soot reduction.”); id. at 56:1-11 (“A. The addition of NO2 to a large surplus of
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`O2 can serve to reduce the temperature needed to combust the soot. So that’s well-
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`known. Q. Okay. And that was well-known as of August 2003? A. I believe so,
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`yes. Q. And that was an important consideration in passive filter regeneration as
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`of August 2003? A. I believe so, yes.”); id. at 101:23-2 (“As we talked about
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`earlier, NO2 is a very good oxidant of soot and is key to bringing the light-off
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`temperature of soot down and enabling passive regeneration to be more easily
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`accomplished.”). This process of combusting soot on the filter during normal
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`engine operation through the use of NO2 or some other oxidant is referred to in the
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`art as “continuous filter regeneration” or “passive filter regeneration.”
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`Even through the use of NO2 for the oxidation of soot, not all soot is
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`oxidized and eventually the filter becomes filled with soot. As a result,
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`backpressure builds up behind the filter, which can impact performance or even
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`stop the engine. See Crocker Decl. ¶ 26, 33. To remove the soot build-up, a
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`process known as “active filter regeneration” is thus required. During this process,
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`the filter is brought up to high temperatures sometimes exceeding 800ºC such that
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`there is combustion of any soot that remains in the filter. Id. ¶¶ 26, 33-34.
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`As of 2003, the conventional wisdom was that the filter needed to have a
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`high mass so that its overall temperature did not increase during active filter
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`regeneration and cause the filter to crack or melt. Id. ¶ 35. Thus, the Heck
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`reference teaches that “the temperature increase during regeneration can be
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`reduced simply by increasing the mass per unit volume of cordierite filter. An
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`increase in filter mass per unit volume may be achieved by increasing the filter cell
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`density (cells per unit area) or wall thickness, or decreasing the percent porosity in
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`the filter walls.” Ex. 1011 at 242 (citation omitted); see also Ex. 2026 [Tennent
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`Tr.] at 131:8-19 (“Q. And so in 2005 the belief of the skilled artisan was that due
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`to the low thermal expansion – excuse me – the low heat capacity of cordierite,
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`you had to have thicker walls? A. Yes. Q. And that was the understanding in
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`2003 as well? A. Yes.”).
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`As of 2003, the skilled artisan understood that increasing filter porosity
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`would make the filter less likely to survive the extreme temperatures of filter
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`regeneration, not just because there was less material to absorb heat, but also
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`because the pores would disrupt the thermal conductivity of the filter. See, e.g.,
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`Ex. 2026 [Tennent Tr.] at 140:9-21 (“And when you add porosity to any filter
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`material, you increase the torturous path, it will decrease the effect of thermal
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`conductance. Q. And that was understood not just in 2006 but in 2003 as well? A.
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`Just a fundamental physical property; yes. Q. And that was the conventional
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`wisdom in 2003 regarding the parameters that would impact the survivability of a
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`filter? A. Absolutely.”).
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`Importantly, the behavior of a filter under soot-loaded conditions was not
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`predictable in 2003 and was the subject of intense study. See Crocker Decl. ¶ 36.
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`For instance, one study in 2002 examined the backpressure of a loaded soot filter
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`as a function of increasing pore size. “Counter to intuition,” the researchers
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`“showed that increasing pore diameter does not necessarily translate to decreased
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`filter back pressure as the pores quickly fill up with soot.” Ex. 2028.007. In 2003,
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`the skilled artisan understood that one could not predict in advance the specific
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`behavior of a filter under soot loaded conditions and/or during active filter
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`regeneration and that this depended on a multiplicity of variables. Crocker Decl. ¶
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`36see also Ex. 2025 [Harold Tr.] at 46:1- 48:14.
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`2.
`The State Of The Art Of NOx After Treatment
`As of 2003, the primary technique for reducing NOx emissions was exhaust
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`gas recirculation (“EGR”). Crocker Decl. ¶ 37; see also Ex. 1011 at 188
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`(“Presently the engine control strategy of exhaust gas recycle (EGR) is being used
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`to reduce the engine out NOx emissions.”). In the EGR approach to reducing NOx,
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`“[p]art of the exhaust of O2 and enriched in H2O and CO2, is recycled back to the
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`combustion chamber. The presence of the H2O and CO2 reduces the average
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`combustion temperature, limiting NOx production.” Ex. 1011 at 191. Although
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`this limits NOx, it “leads to greater particulate and especially dry soot formation
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`and lower fuel economy.” Id.
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`Another approach to reducing NOx that was in use in 2003 was the NOx trap,
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`which is also referred to in the art as a NOx adsorption catalyst. In this approach,
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`an “alkaline metal oxide trap is included to adsorb NOx during the lean mode of
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`operation….The engine will typically operate in the fuel economy lean mode for
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`up to about 60 s, after which hydrocarbon is injected into the exhaust, creating a
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`fuel rich condition for less than one second. The NO2 is desorbed and reduced on
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`the Rh component of the catalyst.” Id. at 206-207.
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`Finally,