(658c) Catalyst Preparation Using Controlled Pt Deposition Onto Well-Defined CeO2 Nanostructures Using Atomic Layer Deposition

Catalyst Preparation Using Controlled Pt deposition onto well-

defined CeO₂ nanostructures using Atomic Layer Deposition

Haibin Zheng, Lilli Eleanor Carpo, Helena Hagelin-Weaver

University of Florida, Gainesville,
U.S.A.

Email: coastzheng@ufl.edu

In recent years, ceria-supported catalysts have been
studied extensively, mainly due to the oxygen storage capacity (OCS) of ceria and
its ability to induce strong metal-support interactions. Many studies have been
performed over CeO₂-supported catalysts and suggest that the
metal-support interface plays an important role during the redox reactions. In
an attempt to facilitate determining structure-activity relationships and
comparisons to theoretical studies, we prepare well-defined catalysts by
supporting active metals onto CeO₂nanoshapes.  The benefit of using well-defined CeO₂nanoshapes is that CeO₂nano-octahedra have a (1 1 1) surface termination, while
the CeO₂nano-rods consist of (1 0 0) and
(1 1 0) surface facets.  Thus, the CeO₂nanoshapes allow us to investigate the effects of CeO₂
surface facets on the active metal, such as platinum. To obtain better control
over the active metal deposition, compared with conventional catalyst preparation
techniques, we used atomic layer deposition of platinum onto the CeO₂nanoshapes.  Early
results demonstrate that the sizes and the amount of the Pt nanoparticles can
be fine-tuned by adjusting the ALD conditions (such as deposition temperature
and time, as well as number of ALD cycles). Moreover, preliminary CO oxidation data
over the prepared catalysts reveal that the support structure can strongly
influence not only the Pt deposition, but also the catalytic actives.  Characterizations of these catalysts are
underway to obtain a better understanding of the metal-support interactions of
these catalysts.