(617ha) Fast Prediction of CO Oxidation Activity on Rare-Earth Metal Doped CeO2

Kim, K., University of Seoul
Han, J. W., University of Seoul
Jung, W., KAIST
Yoo, J., KAIST
Lee, S., KAIST

Prediction of CO Oxidation Activity on Rare-Earth Metal Doped CeO2


Kim1, JeongDo Yoo2, Siwon Lee2,
WooChul Jung2, and Jeong Woo Han1,*

1Department of Chemical Engineering,
University of Seoul, Seoul 130-743, Republic of Korea

2Department of Materials Science and Engineering, Korea
Advanced Institute of Technology, Daejeon 305-701, Republic of Korea

*E-mail: jwhan@uos.ac.kr

Owing to high oxygen storage capacity and high stability over the wide range of temperatures, CeO2 has
been widely applied to support materials for the electrode of solid oxide fuel
cells or diverse oxidation catalysts. While there have
been several studies for understanding the catalytic activity according to the
rare-earth (RE) metal dopants on CeO2 nanoparticles, it is hard to find
the detailed reaction mechanism and a simple descriptor which enables to
rapidly estimate the activity. In this study, our combinatorial study of experiments
and theories shows the catalytic activities of CO oxidation are in order of CeO2
> Ce0.8Pr0.2O2 (PDC) > Ce0.8Nd0.2O2
(NDC) > Ce0.8Sm0.2O2 (SDC). Our density
functional theory calculations demonstrated that CO oxidation reaction on
RE-doped CeO2(111) is well described via the Mars-Van Krevelen (MvK)
mechanism (Fig. 1). We found that the ionic radius of dopants can be used as a simple
descriptor to predict the whole reaction activity (Fig. 2). Based on our
results, we suggest that La might be a promising dopant to enhance the
catalytic activity of CO oxidation. Our results will provide useful insight to
unravel and predict the CO oxidation activity of ceria based catalysts.

Figure 1 Relative
energy diagram of CO oxidation on RE-doped CeO2(111).


Figure 2 Linear
relationship between maximum reaction energy for CO oxidation and ionic radius
of dopants on RE-doped CeO2(111).