The promotive effects of cerium oxide on commercial three-way catalysts (TWCs) for purification of motor exhaust gases have been widely investigated in recent years. This work shows the cooperative effects of CeO2-Pd on the kinetics of CO oxidation over Pd/CeO2-ZrO2. Under reducing-to-moderately oxidizing conditions, a zero-order O2 pressure dependence is found which can be interpreted on the basis of a mechanism involving a reaction between CO adsorbed on Pd and surface oxygen from the support. The high oxygen-exchange capability of the CeO2-ZrO2 support, as determined from temperature-programmed reduction/oxygen uptake measurements is suggested as being responsible for such a catalytic behavior.
CO oxidation on Pd/CeO2-ZrO2 catalysts
FORNASIERO, Paolo;KASPAR, JAN;GRAZIANI, MAURO
1998-01-01
Abstract
The promotive effects of cerium oxide on commercial three-way catalysts (TWCs) for purification of motor exhaust gases have been widely investigated in recent years. This work shows the cooperative effects of CeO2-Pd on the kinetics of CO oxidation over Pd/CeO2-ZrO2. Under reducing-to-moderately oxidizing conditions, a zero-order O2 pressure dependence is found which can be interpreted on the basis of a mechanism involving a reaction between CO adsorbed on Pd and surface oxygen from the support. The high oxygen-exchange capability of the CeO2-ZrO2 support, as determined from temperature-programmed reduction/oxygen uptake measurements is suggested as being responsible for such a catalytic behavior.Pubblicazioni consigliate
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