Federal Circuit clears the air in a catalyst dispute
BASF Corporation v. Johnson Matthey, Inc.
Decided: November 20, 2017
Case Summary by Frederick Hadidi
To reduce emissions of nitrogen oxides (which contribute to smog), some diesel-burning vehicles add ammonia to the exhaust stream. A process called selective catalytic reduction (SCR) combines the nitrogen oxides and ammonia to create nitrogen gas and water.
BASF Corporation’s US Patent 8,524,185 recognized that the SCR reaction does not consume all of the ammonia introduced into the exhaust stream; this is a problem because ammonia is both an irritant and has a strong smell. To solve this problem, the ‘185 patent discloses a catalytic converter that uses two catalysts—one that performs the SCR (nitrogen oxides/ammonia) reaction, and a downstream catalyst that performs an ammonia oxidation
reaction to neutralize the remaining ammonia.
The patent’s specification explains that it is the location of these two catalysts within the catalytic converter—not the composition of each catalyst—that is a patentable advance over the prior art. Consistent with this, the patent’s claims recite mainly structural limitations, but also recite two “material compositions:” one that is “effective to catalyze selective catalytic
reduction (SCR) of NOx [nitrogen oxides],” and another that is “effective for catalyzing NH3 [ammonia] oxidation.” Are these claims indefinite because they do not recite the specific chemical compositions of the two catalysts? In an appeal from a District Court litigation, the US Court of Appeals for the Federal Circuit said no.
At the District Court, defendant Johnson Matthey argued that the claims’ “effective to catalyze/effective for catalyzing” language is indefinite because it is functional, and there are no objective boundaries on what amount of effectiveness is required (or how to measure it); moreover, because the claims recite a “performance property” of the materials (that they are
“effective to catalyze” certain reactions)—rather than their actual compositions—it would be impossible for an ordinary artisan to determine which specific materials are covered by the claim and which are not. The District Court agreed and held the claims to be invalid as indefinite.
The Federal Circuit reversed and remanded. The opinion begins with the standard for indefiniteness established by the Supreme Court in Nautilus v. Biosig, which explains that a claim is indefinite only if it “fails to inform, with reasonable certainty” a skilled artisan about the scope of the invention. The panel then said that that nothing within this standard necessarily
prevents a skilled artisan from understanding with reasonable certainty which compositions perform a particular claimed function.
In ruling that the functional (“effective to catalyze”) language at issue here provides the required reasonable certainty, the Court said that the ‘185 patent both identifies the specific stoichiometric chemical reactions the catalysts enable and gives examples of the types of materials that may be used for each type of catalyst. Finally, the panel rejected the District Court’s concern that a skilled artisan would not be able to determine whether a particular catalyst is “effective” enough to fall within the claims, pointing out that the specification makes clear that any known SCR and ammonia oxidation catalysts may be used in the claimed catalytic converter, and noting that both parties’ experts agreed that catalysts capable of performing the claimed reactions (and tests to determine the effectiveness of those
catalysts) were known at the time of the invention.