Analysis of active sites on copper ion-exchanged ZSM-5 for CO adsorption through IR and adsorption-heat measurements

Yasushige Kuroda, Yuzo Yoshikawa, Ryotaro Kumashiro, Mahiko Nagao

Research output: Contribution to journalArticle

74 Citations (Scopus)

Abstract

The state of copper ion exchanged in ZSM-5-type zeolite has been investigated through the IR and adsorption-heat measurements at 301 K by using CO as a probe molecule. As a result, it was proved that there are at least three kinds of adsorption sites for a CO molecule on the copper ion-exchanged ZSM-5, which are responsible for the IR bands at 2159, 2149, and 2136 cm-1, as well as the differential adsorption-heats of 91, 82, and ∼70 kJ mol-1. Corresponding to these data, TPD also gives three desorption peaks at 363, 442, and 542 K. An excellent linear relationship has been established between the stretching vibrational frequencies due to the adsorbed CO species and the differential adsorption-heat values. When CO gas is introduced to the 723 K-treated sodium ion-exchanged ZSM-5, this sample provides the adsorption-heat of about 35 kJ mol-1 in the whole adsorption region studied and the weak IR bands at 2175 and 2112 cm-1. For the sodium ion-exchanged ZSM-5 and CO system, the above correlation does not hold in the same plot containing Cu-CO species. This fact is interpreted in terms of the difference in the nature of bonding between the electrostatic force for the sodium ion-exchanged ZSM-5 and CO system and the covalent nature for the copper ion-exchanged ZSM-5 and CO system. More detailed discussions are also made on the nature of the Cu-CO bond.

Original languageEnglish
Pages (from-to)6497-6503
Number of pages7
JournalJournal of Physical Chemistry B
Volume101
Issue number33
Publication statusPublished - Aug 14 1997

Fingerprint

Thermal variables measurement
Carbon Monoxide
Copper
heat measurement
Ions
Adsorption
copper
adsorption
ions
Sodium
sodium
heat
Molecules
Electrostatic force
Vibrational spectra
Temperature programmed desorption
Stretching
molecules
Desorption
plots

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Engineering(all)

Cite this

Analysis of active sites on copper ion-exchanged ZSM-5 for CO adsorption through IR and adsorption-heat measurements. / Kuroda, Yasushige; Yoshikawa, Yuzo; Kumashiro, Ryotaro; Nagao, Mahiko.

In: Journal of Physical Chemistry B, Vol. 101, No. 33, 14.08.1997, p. 6497-6503.

Research output: Contribution to journalArticle

@article{1216dffad28d4f39a4f50f85bef51a26,
title = "Analysis of active sites on copper ion-exchanged ZSM-5 for CO adsorption through IR and adsorption-heat measurements",
abstract = "The state of copper ion exchanged in ZSM-5-type zeolite has been investigated through the IR and adsorption-heat measurements at 301 K by using CO as a probe molecule. As a result, it was proved that there are at least three kinds of adsorption sites for a CO molecule on the copper ion-exchanged ZSM-5, which are responsible for the IR bands at 2159, 2149, and 2136 cm-1, as well as the differential adsorption-heats of 91, 82, and ∼70 kJ mol-1. Corresponding to these data, TPD also gives three desorption peaks at 363, 442, and 542 K. An excellent linear relationship has been established between the stretching vibrational frequencies due to the adsorbed CO species and the differential adsorption-heat values. When CO gas is introduced to the 723 K-treated sodium ion-exchanged ZSM-5, this sample provides the adsorption-heat of about 35 kJ mol-1 in the whole adsorption region studied and the weak IR bands at 2175 and 2112 cm-1. For the sodium ion-exchanged ZSM-5 and CO system, the above correlation does not hold in the same plot containing Cu-CO species. This fact is interpreted in terms of the difference in the nature of bonding between the electrostatic force for the sodium ion-exchanged ZSM-5 and CO system and the covalent nature for the copper ion-exchanged ZSM-5 and CO system. More detailed discussions are also made on the nature of the Cu-CO bond.",
author = "Yasushige Kuroda and Yuzo Yoshikawa and Ryotaro Kumashiro and Mahiko Nagao",
year = "1997",
month = "8",
day = "14",
language = "English",
volume = "101",
pages = "6497--6503",
journal = "Journal of Physical Chemistry B Materials",
issn = "1520-6106",
publisher = "American Chemical Society",
number = "33",

}

TY - JOUR

T1 - Analysis of active sites on copper ion-exchanged ZSM-5 for CO adsorption through IR and adsorption-heat measurements

AU - Kuroda, Yasushige

AU - Yoshikawa, Yuzo

AU - Kumashiro, Ryotaro

AU - Nagao, Mahiko

PY - 1997/8/14

Y1 - 1997/8/14

N2 - The state of copper ion exchanged in ZSM-5-type zeolite has been investigated through the IR and adsorption-heat measurements at 301 K by using CO as a probe molecule. As a result, it was proved that there are at least three kinds of adsorption sites for a CO molecule on the copper ion-exchanged ZSM-5, which are responsible for the IR bands at 2159, 2149, and 2136 cm-1, as well as the differential adsorption-heats of 91, 82, and ∼70 kJ mol-1. Corresponding to these data, TPD also gives three desorption peaks at 363, 442, and 542 K. An excellent linear relationship has been established between the stretching vibrational frequencies due to the adsorbed CO species and the differential adsorption-heat values. When CO gas is introduced to the 723 K-treated sodium ion-exchanged ZSM-5, this sample provides the adsorption-heat of about 35 kJ mol-1 in the whole adsorption region studied and the weak IR bands at 2175 and 2112 cm-1. For the sodium ion-exchanged ZSM-5 and CO system, the above correlation does not hold in the same plot containing Cu-CO species. This fact is interpreted in terms of the difference in the nature of bonding between the electrostatic force for the sodium ion-exchanged ZSM-5 and CO system and the covalent nature for the copper ion-exchanged ZSM-5 and CO system. More detailed discussions are also made on the nature of the Cu-CO bond.

AB - The state of copper ion exchanged in ZSM-5-type zeolite has been investigated through the IR and adsorption-heat measurements at 301 K by using CO as a probe molecule. As a result, it was proved that there are at least three kinds of adsorption sites for a CO molecule on the copper ion-exchanged ZSM-5, which are responsible for the IR bands at 2159, 2149, and 2136 cm-1, as well as the differential adsorption-heats of 91, 82, and ∼70 kJ mol-1. Corresponding to these data, TPD also gives three desorption peaks at 363, 442, and 542 K. An excellent linear relationship has been established between the stretching vibrational frequencies due to the adsorbed CO species and the differential adsorption-heat values. When CO gas is introduced to the 723 K-treated sodium ion-exchanged ZSM-5, this sample provides the adsorption-heat of about 35 kJ mol-1 in the whole adsorption region studied and the weak IR bands at 2175 and 2112 cm-1. For the sodium ion-exchanged ZSM-5 and CO system, the above correlation does not hold in the same plot containing Cu-CO species. This fact is interpreted in terms of the difference in the nature of bonding between the electrostatic force for the sodium ion-exchanged ZSM-5 and CO system and the covalent nature for the copper ion-exchanged ZSM-5 and CO system. More detailed discussions are also made on the nature of the Cu-CO bond.

UR - http://www.scopus.com/inward/record.url?scp=0031213252&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0031213252&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0031213252

VL - 101

SP - 6497

EP - 6503

JO - Journal of Physical Chemistry B Materials

JF - Journal of Physical Chemistry B Materials

SN - 1520-6106

IS - 33

ER -