17O-EPR determination of the structure and dynamics of copper single-metal sites in zeolites

Paolo Cleto Bruzzese; Enrico Salvadori; Stefan Jäger; Martin Hartmann; Bartolomeo Civalleri; Andreas Pöppl; Mario Chiesa

doi:10.1038/s41467-021-24935-7

¹⁷O-EPR determination of the structure and dynamics of copper single-metal sites in zeolites

Nat Commun. 2021 Jul 30;12(1):4638. doi: 10.1038/s41467-021-24935-7.

Authors

Paolo Cleto Bruzzese^{1

2}, Enrico Salvadori², Stefan Jäger³, Martin Hartmann³, Bartolomeo Civalleri², Andreas Pöppl⁴, Mario Chiesa⁵

Affiliations

¹ Felix Bloch Institute for Solid State Physics, Universität Leipzig, Leipzig, Germany.
² Department of Chemistry and NIS Centre of Excellence, University of Turin, Torino, Italy.
³ Erlangen Center for Interface Research and Catalysis (ECRC), Erlangen, Germany.
⁴ Felix Bloch Institute for Solid State Physics, Universität Leipzig, Leipzig, Germany. poeppl@physik.uni-leipzig.de.
⁵ Department of Chemistry and NIS Centre of Excellence, University of Turin, Torino, Italy. mario.chiesa@unito.it.

Abstract

The bonding of copper ions to lattice oxygens dictates the activity and selectivity of copper exchanged zeolites. By ¹⁷O isotopic labelling of the zeolite framework, in conjunction with advanced EPR methodologies and DFT modelling, we determine the local structure of single site Cu^II species, we quantify the covalency of the metal-framework bond and we assess how this scenario is modified by the presence of solvating H₂¹⁶O or H₂¹⁷O molecules. This enables to follow the migration of Cu^II species as a function of hydration conditions, providing evidence for a reversible transfer pathway within the zeolite cage as a function of the water pressure. The results presented in this paper establish ¹⁷O EPR as a versatile tool for characterizing metal-oxide interactions in open-shell systems.

Abstract

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