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

Authors :
Andreas Pöppl
Enrico Salvadori
Stefan Jäger
Bartolomeo Civalleri
Mario Chiesa
Paolo Cleto Bruzzese
Martin Hartmann
Source :
Nature Communications, Nature Communications, Vol 12, Iss 1, Pp 1-13 (2021)
Publication Year :
2021
Publisher :
Springer Science and Business Media LLC, 2021.

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 CuII 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 CuII 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.<br />The identification of catalytically active sites with atomic-scale precision occupies a central place in the theory and practice of heterogeneous catalysis. Here the authors assess the nature of the copper-oxygen bond in a Cu-CHA zeolite and recover the microscopic structure of single-metal sites.

Details

ISSN :
20411723
Volume :
12
Database :
OpenAIRE
Journal :
Nature Communications
Accession number :
edsair.doi.dedup.....99f058acbf887346c15da62186e7d034
Full Text :
https://doi.org/10.1038/s41467-021-24935-7