Thermal analysis and EPR study of copper species in mordenites prepared by conventional and microwave-assisted methods

Marina Shelyapina, Irina Zvereva, Lilia Yafarova, Dmitrii Bogdanov, Stanislav Sukharzhevskii, Yurii Zhukov, V. Petranovskii

Research output

3 Citations (Scopus)

Abstract

Copper-exchanged mordenites prepared by different methods, conventional and microwave assisted, have been investigated
by TG, DSC, temperature-programmed reduction (TPR), and EPR methods. TPR study of hydrated and annealed at
573 and 973 K samples revealed that the copper reduction occurs directly from Cu2? to Cu0, and Cu2? ions are in different
local environments. The microwave-assisted treatment leads to formation of [Cu–O–Cu]2? species in the main mordenite
channels. The most easily recoverable copper in the fully hydrated samples corresponds to the individual Cu2? ions
coordinated by H2O molecules, and the number of these [Cu(H2O)n]2? complexes does not depend on the preparation
method and the total copper content. According to the EPR study, upon sample dehydration, [Cu(H2O)n]2? species lose
water and approach the wall of the zeolite forming a bond with reversible charge transfer from a framework oxygen to
Cu2?.
Original languageEnglish
Pages (from-to)71-79
Number of pages9
JournalJournal of Thermal Analysis and Calorimetry
Volume134
Issue number1
Early online date1 Feb 2018
DOIs
Publication statusE-pub ahead of print - 1 Feb 2018

Cite this

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title = "Thermal analysis and EPR study of copper species in mordenites prepared by conventional and microwave-assisted methods",
abstract = "Copper-exchanged mordenites prepared by different methods, conventional and microwave assisted, have been investigatedby TG, DSC, temperature-programmed reduction (TPR), and EPR methods. TPR study of hydrated and annealed at573 and 973 K samples revealed that the copper reduction occurs directly from Cu2? to Cu0, and Cu2? ions are in differentlocal environments. The microwave-assisted treatment leads to formation of [Cu–O–Cu]2? species in the main mordenitechannels. The most easily recoverable copper in the fully hydrated samples corresponds to the individual Cu2? ionscoordinated by H2O molecules, and the number of these [Cu(H2O)n]2? complexes does not depend on the preparationmethod and the total copper content. According to the EPR study, upon sample dehydration, [Cu(H2O)n]2? species losewater and approach the wall of the zeolite forming a bond with reversible charge transfer from a framework oxygen toCu2?.",
author = "Marina Shelyapina and Irina Zvereva and Lilia Yafarova and Dmitrii Bogdanov and Stanislav Sukharzhevskii and Yurii Zhukov and V. Petranovskii",
year = "2018",
month = "2",
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doi = "10.1007/s10973-018-7016-2",
language = "English",
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journal = "Journal of Thermal Analysis and Calorimetry",
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TY - JOUR

T1 - Thermal analysis and EPR study of copper species in mordenites prepared by conventional and microwave-assisted methods

AU - Shelyapina, Marina

AU - Zvereva, Irina

AU - Yafarova, Lilia

AU - Bogdanov, Dmitrii

AU - Sukharzhevskii, Stanislav

AU - Zhukov, Yurii

AU - Petranovskii, V.

PY - 2018/2/1

Y1 - 2018/2/1

N2 - Copper-exchanged mordenites prepared by different methods, conventional and microwave assisted, have been investigatedby TG, DSC, temperature-programmed reduction (TPR), and EPR methods. TPR study of hydrated and annealed at573 and 973 K samples revealed that the copper reduction occurs directly from Cu2? to Cu0, and Cu2? ions are in differentlocal environments. The microwave-assisted treatment leads to formation of [Cu–O–Cu]2? species in the main mordenitechannels. The most easily recoverable copper in the fully hydrated samples corresponds to the individual Cu2? ionscoordinated by H2O molecules, and the number of these [Cu(H2O)n]2? complexes does not depend on the preparationmethod and the total copper content. According to the EPR study, upon sample dehydration, [Cu(H2O)n]2? species losewater and approach the wall of the zeolite forming a bond with reversible charge transfer from a framework oxygen toCu2?.

AB - Copper-exchanged mordenites prepared by different methods, conventional and microwave assisted, have been investigatedby TG, DSC, temperature-programmed reduction (TPR), and EPR methods. TPR study of hydrated and annealed at573 and 973 K samples revealed that the copper reduction occurs directly from Cu2? to Cu0, and Cu2? ions are in differentlocal environments. The microwave-assisted treatment leads to formation of [Cu–O–Cu]2? species in the main mordenitechannels. The most easily recoverable copper in the fully hydrated samples corresponds to the individual Cu2? ionscoordinated by H2O molecules, and the number of these [Cu(H2O)n]2? complexes does not depend on the preparationmethod and the total copper content. According to the EPR study, upon sample dehydration, [Cu(H2O)n]2? species losewater and approach the wall of the zeolite forming a bond with reversible charge transfer from a framework oxygen toCu2?.

U2 - 10.1007/s10973-018-7016-2

DO - 10.1007/s10973-018-7016-2

M3 - Article

VL - 134

SP - 71

EP - 79

JO - Journal of Thermal Analysis and Calorimetry

JF - Journal of Thermal Analysis and Calorimetry

SN - 1388-6150

IS - 1

ER -