Appeal 2006-2522
Application 10/279,632
is taught by the prior art to be useful for the same purpose. In re Kerkhoven,
626 F.2d 846, 850, 205 USPQ 1069, 1072 (CCPA 1980). Consequently, we
are in full agreement with the Examiner’s legal conclusion that it would
have been obvious for one of ordinary skill in the art to use a combination of
different platinum catalysts for the cathodes of Chun and Isono with the
reasonable expectation that the resultant cathode would perform effectively
in the fuel cells. Indeed, as pointed out by the Examiner, Surampudi
expressly teaches that “[t]he cathode catalyst ink is preferably pure platinum,
although other inks can be used and other materials can be mixed into the
ink as described herein” (col. 12, ll. 47-51, emphasis added). Significantly,
Appellants advance no argument based on unexpected results attributed to
the broadly-claimed combination of different catalysts. In the absence of
such evidence, the Examiner’s prima case of obviousness stands unrebutted.
Appellants contend that “one skilled in the art would not be motivated
to modify a particular cathode design by adding additional elements, such as
another catalyst, because doing so could complicate the manufacture of the
cathode and/or increase the cost associated with manufacturing the cathode”
(Br. 3, second paragraph, last sentence). However, even though the cost of
using different catalysts may be greater than using only one, the scarcity or
unavailability of one may compel the use of more than one catalyst.
Moreover, Appellants have not established that their use of different
catalysts does not, unexpectedly, complicate the manufacture of the cathode
or increase the cost.
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