Identifying Active Oxygen and Copper Species in Cu/CeO2 Catalysts Using Raman and UV–Vis Modulation Excitation Spectroscopy Modulation excitation spectroscopy (MES) with so-called phase-sensitive detection (PSD) is receiving increasing attention for the identification of active species and the elucidation of reaction mechanisms in heterogeneous catalysis. We report the combination of Raman- and UV–vis-MES to be a powerful approach to gain new mechanistic insight into oxide-supported metal catalysts, as illustrated for the CO oxidation over low-loaded Cu/CeO2 catalysts. Due to the enhanced sensitivity of the MES/PSD approach, Raman spectroscopy provides direct evidence for the active participation of surface lattice oxygen of the ceria support in the reaction mechanism. While Raman-MES enables exclusive insight into the role of the ceria support, UV–vis-MES is shown to be sensitive to the low copper loading. ME-UV–vis spectra highlight the redox activity of copper species and the electronic interactions between copper and ceria, revealing major reduction of Cu2+ to Cu+ while reduction of Ce4+ to Ce3+ is minor under the studied reaction conditions. Based on the mechanistic findings provided by the combined Raman/UV–vis-MES/PSD methodology, we expect this approach to be a valuable tool to gain information about active species and sites of catalysts relevant for renewable energy.

Congrats to Henrik Hoyer on his recently published front cover for the new article on Raman and UV-Vis modulation excitation over Cu/CeO₂ catalysts! | The Journal of Physical Chemistry C pubs.acs.org/doi/10.1021/...

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Hello, we are a research group from TU Darmstadt, Germany. Could we please be added to post in the science feed? Here a link to our website: www.chemie.tu-darmstadt.de/hess/index.e...