Cerium oxide (CeO
2) has been widely used as an industrial catalyst support due to its high oxygen mobility
1. However, due to its limited bulk reducibility as well as its tendency to deactivate at high temperatures, promoters such as Zr have been doped into the ceria lattice to improve its oxygen storage capacity and catalytic activity
1,2. In the present study, CuO
x/Ce
yZr
1-yO
2 (y = 1, 0.9, 0.6, 0.5, and 0) catalysts with fixed surface density of copper (Cu atoms/nm
2) were synthesized using a novel one-pot chemical vapor deposition (OP-CVD) method and were tested for CO oxidation reaction. The synthesized catalysts were investigated by spectroscopic and microscopic characterization techniques to evaluate the defect sites, metal dispersion, and chemical composition. Raman and XRD results (Fig. 1 (a) and (b)) reveal that the surface CuO
x species were highly dispersed on ceria-based supports. Incorporation of a Zr promoter and CuO
x surface species was investigated for CO oxidation using varied CO:O
2 ratios to investigate a catalytic performance. The effect of the increased availability of defect sites (Fig. 1 (a)) in the Ce
0.6Zr
0.4O
2 and Ce
0.5Zr
0.5O
2-based catalysts can be seen with reaction under equimolar CO/O
2 feeds where their catalytic performance (Fig. (c) and (d)) could have been hindered by the availability of excess oxygen. It is hypothesized that under O
2-lean conditions, the role of defect sites becomes more important in determination of the catalytic activity of CuO
x/Ce
yZr
1-yO
2 catalysts.
Acknowledgements: The authors acknowledge funding support from the National Science Foundation (NSF-CBET-2050824). The authors would also like to thank the Advanced Energy Research and Technology Center (AERTC) for the facilities at Stony Brook University. This research used the beamline 28-ID-1 of the National Synchrotron Light Source II (NSLS-II), which is the U.S. Department of Energy (DOE) Office of Science User Facilities at Brookhaven National Laboratory under Contract No. DE-SC0012704.
