Appeal 2007-2908
Application 10/379,456
Scope and content of the prior art
As discussed above, Liu teaches an ozone-destroying catalytic
converter with a core, a refractory metal oxide washcoat, and first and
second catalysts in the washcoat.
Liu's washcoat has a high surface area to support the catalyst. The
washcoat may be applied directly to the core or to an oxidized layer on the
core. (Liu 4:38-48.) The washcoat may even be applied directly to the
unanodized core. (Liu 10:35-42.) The catalyst could include additional
metals, including more than one precious metal and a transition metal.
(Liu 10:49-54.) Liu's preferred precious metal is palladium, which would
leave silver, platinum, gold, rhodium, and iridium as choices for the second
precious metal. Recall that most of Liu's catalysts and co-catalysts
inherently destroy hydrocarbons as well.
Differences between prior art and the claims
The examiner cites as a difference the specific groupings of active
metals in claim 29. (Examiner's Answer (Ans.) 6-7.) Assuming for the sake
of argument that claim 29 really requires separate groups of claims, the
examiner nevertheless appears to be mistaken about this difference. The
examiner apparently overlooked (and thus apparently did not consider) Liu's
express teaching to use more than one precious metal and a transition metal.
We cannot and do not read claim 29 to exclude the use of more than two
active metals. If, following Liu's teaching, one used two precious metals or
two transition metals, most of the possible trimetallic combinations within
Liu's teaching would also be within the scope of claim 29.
Liu does not teach the use of a catalyst to destroy hydrocarbons. Most
of Liu's ozone-destroying catalysts also destroy hydrocarbons, however,
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