2024 AIChE Annual Meeting
(387f) The Role of a Zr Promoter and CuOx Surface Species in the Facilitation of Oxygen Vacancies in Fixed Surface Density (SD) CuOx/CeyZr1-YO2 Catalysts for CO Oxidation
Authors
Pophali, A. - Presenter, Stony Brook University
Sifat, M., Stony Brook University
Jiang, W., Stony Brook University
Lu, Y., Stony Brook University
Kwon, G., Brookhaven National Laboratory
Yoon, K., Hanyang University
Song, H., Hanyang University
Shim, S. E., INHA University
Kim, T. J., Stony Brook University
Cerium oxide (CeO2) has been widely used as an industrial catalyst support due to its high oxygen mobility1. 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 activity1,2. In the present study, CuOx/CeyZr1-yO2 (y = 1, 0.9, 0.6, 0.5, and 0) catalysts with fixed surface density of copper (Cu atoms/nm2) 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 CuOx species were highly dispersed on ceria-based supports. Incorporation of a Zr promoter and CuOx surface species was investigated for CO oxidation using varied CO:O2 ratios to investigate a catalytic performance. The effect of the increased availability of defect sites (Fig. 1 (a)) in the Ce0.6Zr0.4O2 and Ce0.5Zr0.5O2-based catalysts can be seen with reaction under equimolar CO/O2 feeds where their catalytic performance (Fig. (c) and (d)) could have been hindered by the availability of excess oxygen. It is hypothesized that under O2-lean conditions, the role of defect sites becomes more important in determination of the catalytic activity of CuOx/CeyZr1-yO2 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.