Ex Parte OHMA et al

Patent Trial and Appeal Board

Apr 15, 2016

13551573 (P.T.A.B. Apr. 15, 2016)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR
13/551,573 07/17/2012 Atsushi OHMA
22428 7590 04/19/2016
Foley & Lardner LLP
3000 K STREET N.W.
SUITE 600
WASHINGTON, DC 20007-5109
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www .uspto.gov
ATTORNEY DOCKET NO. CONFIRMATION NO.
040356-0687 1068
EXAMINER
WANG, EUGENIA
ART UNIT PAPER NUMBER
1729
NOTIFICATION DATE DELIVERY MODE
04/19/2016 ELECTRONIC
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address( es):
ipdocketing@foley.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte ATSUSHI OHMA, YOSHITAKA ONO, RYOICHI SHIMO!, and
KAZUY A T AJIRI 1
Appeal2014-002159
Application 13/551,573
Technology Center 1700
Before MICHAEL P. COLAIANNI, CHRISTOPHER M. KAISER, and
CHRISTOPHER C. KENNEDY, Administrative Patent Judges.
KENNEDY, Administrative Patent Judge.
DECISION ON APPEAL
This is an appeal under 35 U.S.C. § 134(a) from a final rejection of
claims 1--4 and 6.2 An oral hearing was held on March 29, 2016. We have
jurisdiction under 35 U.S.C. § 6(b ).
We REVERSE.
1 According to the Appellants, the real party in interest is Nissan Motor Co.,
Ltd. App. Br. 2.
2 The Office Action Summary attached to the Final Action dated February
27, 2013, lists claim 13 as a rejected claim. Claim 13 was cancelled in an
amendment after the Final Action, see Claim Amendments dated May 24,
2013, and is therefore not before us in this appeal.
Appeal2014-002159
Application 13/551,573
BACKGROUND
The subject matter on appeal relates to fuel cells, and, in particular, to
a constitution of a cathode catalyst layer of a polymer electrolyte fuel cell.
Spec. 1:13-14; Claim 1. Claim 1 is reproduced below from page 15 (Claims
Appendix) of the Appeal Brief:
1. A fuel cell comprising:
a solid polymer electrolyte membrane;
a cathode catalyst layer provided on a side of the solid polymer
electrolyte membrane, the cathode catalyst layer comprising
catalyst particles each of which comprises a support and a metal
catalyst supported on the support; and
a cathode separator facing the cathode catalyst layer, the cathode
separator having an oxidant gas passage through which an
oxidant gas flows, on a surface facing the cathode catalyst layer,
and a cooling water passage through which a cooling water
flows, on an opposite surface to the surface facing the cathode
catalyst layer, the oxidant gas passage comprising an upstream
portion and a downstream portion with respect to a flow of the
oxidant gas and the cooling water passage comprising an
upstream portion and a downstream portion with respect to a
flow of the cooling water;
wherein, in a region of the cathode catalyst layer facing an area
in which a the downstream portion of the oxidant gas passage
overlaps an the upstream portion the cooling water passage, a
specific surface area of the particles in the cathode catalyst layer
is greater than in another region of the cathode catalyst layer.
ANALYSIS
All pending claims stand rejected under 35 U.S.C. § 103(a) as
unpatentable over Enjoji et al. (US 2003/0129475 Al, published July 10,
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Application 13/551,573
2003) in view of Breault (US 4,851,377, issued July 25, 1989) and Asaoka et
al. (US 2003/0096156 Al, published May 22, 2003).
The Examiner finds, and the Appellants do not dispute, that Enjoji
teaches a fuel cell comprising each element of claim 1 except for the
"wherein" limitation. Ans. 2-3. The Examiner finds that Breault teaches a
fuel cell catalyst with increased catalyst loading at the downstream portion
of the catalyst to provide a uniform reaction rate, and that Asaoka teaches
that fuel cell catalyst loading can be increased by increasing the surface area
of the catalyst particles. Id. at 3--4. The Examiner concludes that it would
have been obvious to modify the fuel cell of Enjoji to have increased particle
loading "to provide uniform reaction rate," as taught by Breault. Id. at 4.
Largely for reasons set forth by the Appellants, see App. Br. 10, 11,
13, we conclude that a preponderance of the evidence does not support the
Examiner's rejection. The Appellants have persuasively argued that Breault
concerns a co-current flow fuel cell and that Enjoji concerns a counter-
current flow fuel cell. See App. Br. 6-8. While the fuel cell of Breault does
employ increased catalyst loading in the downstream portion of the catalyst
that is necessary because the concentrations of both reactants (the fuel and
the oxidant) decrease as they travel in the same direction through the gas
passages, resulting in an undesirable decrease in reaction rate down the
length of the electrode. E.g., Breault at 1:32-35 ("Reaction rates vary with
location on the electrode and are dependent upon such local factors as
reactant and product concentrations and temperature."). To solve that
problem and maintain a steady reaction rate along the length of the
electrode, Breault teaches the use of increased catalyst loading in the
downstream portion of the electrode to offset the effect of the decreased
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Application 13/551,573
reactant concentrations. E.g., id. at 5:58---62 ("Ideally, the effect of the
increased catalyst loading in the direction of gas flow balances the effect of
the depletion of reactants in the gas stream to result in a reaction rate that is
substantially uniform across the surface of the plate.").
Enjoji concerns a counter-current flow system in which the reactants
flow in opposite directions, rather than in the same direction. E.g., Enjoji
Fig. 1. As the Appellants explain, a person of ordinary skill in the art would
have expected this system to solve the problem of Breault because the
varying concentrations of the reactants along the length of the electrode (i.e.,
high fuel concentration and low oxidant concentration at one end of the
electrode; low fuel concentration and high oxidant concentration at the other
end of the electrode) would result in a relatively constant reaction rate along
the length of the electrode without the need for catalyst loading. See App.
Br. 11. In fact, it appears that, in a counter-current flow system such as that
of Enjoji, increased catalyst loading in the downstream portion of the
cathode catalyst, as proposed by the Examiner, would actually be contrary to
the goal of Breault; i.e., it would result in an increased reaction rate across
the portion of the electrode corresponding to the loaded catalyst, while the
reaction rate in the non-loaded zone would remain the same, resulting in a
non-uniform reaction rate across the length of the electrode (lower rate in the
non-loaded zone; higher rate in the loaded zone). Therefore, a
preponderance of the evidence does not support the Examiner's finding that
a person of ordinary skill in the art would have been motivated "to provide
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Application 13/551,573
larger catalyst loading at the cathode [outlet of Enjoji] ... in order to
provide uniform reaction rate." See Ans. 4.
The Examiner finds that "[ e ]ven if this co-current flow were the
case ... it still does not negate the teaching of Breault ... that reactants [sic]
gases get depleted from inlet to outlet, and thus more loading of a catalyst
must be at the outlet side - as applied [to] Enjoji et al.' s structure." Ans. 10.
We disagree. As explained above, the counter-current flow system ofEnjoji
appears to account for depletion of reactants by having the reactants flow in
opposite directions, which logically would appear to result in a more
uniform reaction rate along the length of the electrode (without the use of
catalyst loading) than the co-current flow system of Breault. The Appellants
have argued that Enjoji's system would not need catalyst loading because it
solves the reaction rate problem in a different way (opposite flow of
reactants), and, as noted above, it appears that the catalyst loading in Enjoji's
system proposed by the Examiner may actually exacerbate the issue of non-
uniform reaction rate. The Examiner has not persuasively responded to the
Appellants' arguments.
The Examiner also states that "Appellant's submission that Breault's
teaching is only applicable to co-current flow fuel cells is akin to saying that
reactants does [sic] not get depleted as they travel from inlet to outlet of
counter-current flow cells, which is repugnant to the very purpose of a fuel
cell .... " Id. at 12. The Appellants, however, do not argue that reactants
are not depleted as they travel from inlet to outlet in Enjoji's fuel cell; they
argue that the flow of reactants in opposite directions (i.e., high fuel
concentration and low oxidant concentration at one end of the electrode; low
fuel concentration and high oxidant concentration at the other end of the
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Application 13/551,573
electrode) accounts for the non-uniform-reaction-rate problem of Breault
without the need for catalyst loading.
In view of the arguments presented, we are not persuaded that a
person of ordinary skill in the art would have been motivated to utilize
increased catalyst loading to solve the problem of non-uniform reaction
rates, as taught by Breault, in the fuel cell of Enjoji. We therefore must
reverse the Examiner's rejection of claim 1. The remaining claims on appeal
depend from claim 1, and the Examiner's rejection of those claims does not
remedy the error identified above. Therefore, we likewise reverse the
Examiner's rejection of claims 2--4 and 6.
CONCLUSION
We REVERSE the Examiner's rejection of claims 1--4 and 6.
REVERSED
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