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Investigation into the Palladium‐Europium Acetate Reductive Decomposition with Synchrotron Radiation‐Based X‐ray Diffraction and X‐ray Absorption Spectroscopy
Author(s) -
Khramov Evgeny,
Belyakova Olga,
Murzin Vadim,
Veligzhanin Alexey,
Chernyshov Alfred,
Vargaftik Mikhail,
Kozitsytalya,
Zubavichus Yan
Publication year - 2014
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/zaac.201400258
Subject(s) - x ray absorption fine structure , europium , xanes , extended x ray absorption fine structure , chemistry , palladium , nanocrystalline material , thermal decomposition , absorption (acoustics) , x ray absorption spectroscopy , palladium hydride , crystallography , materials science , absorption spectroscopy , spectroscopy , analytical chemistry (journal) , hydride , hydrogen , catalysis , organic chemistry , ion , physics , quantum mechanics , composite material
The reductive decomposition of the complex Pd 2 Eu 2 (μ,η 2 ‐OOCMe) 2 (μ‐OOCMe) 8 (H 2 O) 2 · (HOOCMe) 2 upon heating from room temperature to 500 °C in a hydrogen atmosphere was investigated by in situ synchrotron radiation‐based X‐ray absorption fine structure spectroscopy (XAFS) including observations of X‐ray near‐edge structure (XANES) and extended absorption fine structure (EXAFS) at Pd K‐ and Eu L 3 ‐edges and synchrotron X‐ray diffraction (XRD). The Pd‐Eu 2 O 3 nanocomposite was found to be the final thermolysis product. The decomposition proceeds via series of intermediate crystalline phases, including europium(II) and (III) anhydrous acetates and EuO(CH 3 COO) oxidoacetate. Surprisingly, the major fraction of europium occurs in the reduced form Eu 2+ within a limited temperature range of 200–300 °C. Presumably, the reversible Eu 3+ ↔Eu 2+ redox‐process is associated with the stability of nanocrystalline palladium hydride, which acts as a stronger reducing agent as compared to molecular hydrogen.