期刊
ACS CATALYSIS
卷 4, 期 6, 页码 1650-1661出版社
AMER CHEMICAL SOC
DOI: 10.1021/cs500148e
关键词
Operando catalysis; XANES; DRIFTS; CO oxidation; copper; ceria
资金
- Division of Chemical Sciences, Geosciences, and Biosciences, Office of Basic Energy Sciences of the U.S. Department of Energy [DE-AC02-98CH10886]
- U.S. DOE [DE-AC02-06CH11357]
- China Scholarship Council [201206010107]
- MINECO [CTQ2012-32928]
- EU COST [CM1104 action]
The redox chemistry and CO oxidation (2CO + O-2 -> 2CO(2)) activity of catalysts generated by the dispersion of CuO on CeO2 nanorods were investigated using a multitechnique approach. Combined measurements of time-resolved X-ray absorption near-edge spectroscopy (XANES) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) in one setup were made possible with the development of a novel reaction cell in which fluorescence mode detection was applied to collect the XANES spectra. This is the first reported example using XANES in a similar technique combination. With the assistance of parallel time-resolved X-ray diffraction (XRD) measurements under operando conditions, we successfully probed the redox behavior of CuO/CeO2 under CO reduction, constant-flow (steady-state) CO oxidation and during CO/O-2 cycling reactions. A strong copper <-> ceria synergistic effect was observed in the CuO/CeO2 catalyst. Surface Cu(I) species were found to exhibit a strong correlation with the catalyst activity for the CO oxidation reaction. By analysis of phase transformations as well as changes in oxidation state during the nonsteady states in the CO/O-2 cycling reaction, we collected information on the relative transformation rates of key species. Elementary steps in the mechanism for the CO oxidation reaction are proposed based on the understandings gained from the XANES/DRIFTS operando studies.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据