Role of basic and acidic centers of MgO and modified MgO in catalytic transfer hydrogenation of ketones studied by infrared spectroscopy

Research output: Contribution to journalArticle

31 Citations (Scopus)

Abstract

In this study our aim was to identify the active sites and the surface species responsible for deactivation of MgO during catalytic transfer hydrogenations (CTH) of ketones using alcohols as hydrogen donors. Our previous studies showed that deactivation of MgO could be prevented by previous treatment with chloromethanes. Therefore the surface species formed during the reaction were studied before and after treatment with chloroform or chloroform-d by in situ infrared spectroscopy (IR). As a result, it was concluded that the reaction requires the presence of surface basic andacidic centers. The presence of Lewis acid centers was not necessary, the reaction could proceed on weakly acidic surface Bronsted sites, as the alterations in intensity and position of the v(OH) bands indicated. Modification with chloroform resulted also in the generation of surface OH groups with a proper acidity for the reaction. The shift in carbonyl vibrations led us to the conclusion that Lewis acid and base centers were responsible for the catalyst poisoning, so covering these acid sites by Cl- led to a stable catalyst.

Original languageEnglish
Pages (from-to)13-17
Number of pages5
JournalJournal of Molecular Structure
Volume482-483
DOIs
Publication statusPublished - May 25 1999

Fingerprint

Hydrogenation
Chloroform
Ketones
ketones
hydrogenation
Infrared spectroscopy
Lewis Acids
Spectrum Analysis
infrared spectroscopy
chloroform
Lewis Bases
Methyl Chloride
deactivation
acids
Vibration
Poisoning
Hydrogen
Catalyst poisoning
Catalytic Domain
catalysts

Keywords

  • 2-Butanone
  • 2-Propanol
  • Active centers
  • Chloroform
  • Chloroform- d
  • FT-IR spectroscopy
  • Magnesium oxide
  • Surface species

ASJC Scopus subject areas

  • Structural Biology
  • Organic Chemistry
  • Physical and Theoretical Chemistry
  • Spectroscopy
  • Atomic and Molecular Physics, and Optics

Cite this

@article{03f1ae5989324db09c09ffab6d8aaaf2,
title = "Role of basic and acidic centers of MgO and modified MgO in catalytic transfer hydrogenation of ketones studied by infrared spectroscopy",
abstract = "In this study our aim was to identify the active sites and the surface species responsible for deactivation of MgO during catalytic transfer hydrogenations (CTH) of ketones using alcohols as hydrogen donors. Our previous studies showed that deactivation of MgO could be prevented by previous treatment with chloromethanes. Therefore the surface species formed during the reaction were studied before and after treatment with chloroform or chloroform-d by in situ infrared spectroscopy (IR). As a result, it was concluded that the reaction requires the presence of surface basic andacidic centers. The presence of Lewis acid centers was not necessary, the reaction could proceed on weakly acidic surface Bronsted sites, as the alterations in intensity and position of the v(OH) bands indicated. Modification with chloroform resulted also in the generation of surface OH groups with a proper acidity for the reaction. The shift in carbonyl vibrations led us to the conclusion that Lewis acid and base centers were responsible for the catalyst poisoning, so covering these acid sites by Cl- led to a stable catalyst.",
keywords = "2-Butanone, 2-Propanol, Active centers, Chloroform, Chloroform- d, FT-IR spectroscopy, Magnesium oxide, Surface species",
author = "G. Sz{\"o}llősi and M. Bart{\'o}k",
year = "1999",
month = "5",
day = "25",
doi = "10.1016/S0022-2860(98)00833-3",
language = "English",
volume = "482-483",
pages = "13--17",
journal = "Journal of Molecular Structure",
issn = "0022-2860",
publisher = "Elsevier",

}

TY - JOUR

T1 - Role of basic and acidic centers of MgO and modified MgO in catalytic transfer hydrogenation of ketones studied by infrared spectroscopy

AU - Szöllősi, G.

AU - Bartók, M.

PY - 1999/5/25

Y1 - 1999/5/25

N2 - In this study our aim was to identify the active sites and the surface species responsible for deactivation of MgO during catalytic transfer hydrogenations (CTH) of ketones using alcohols as hydrogen donors. Our previous studies showed that deactivation of MgO could be prevented by previous treatment with chloromethanes. Therefore the surface species formed during the reaction were studied before and after treatment with chloroform or chloroform-d by in situ infrared spectroscopy (IR). As a result, it was concluded that the reaction requires the presence of surface basic andacidic centers. The presence of Lewis acid centers was not necessary, the reaction could proceed on weakly acidic surface Bronsted sites, as the alterations in intensity and position of the v(OH) bands indicated. Modification with chloroform resulted also in the generation of surface OH groups with a proper acidity for the reaction. The shift in carbonyl vibrations led us to the conclusion that Lewis acid and base centers were responsible for the catalyst poisoning, so covering these acid sites by Cl- led to a stable catalyst.

AB - In this study our aim was to identify the active sites and the surface species responsible for deactivation of MgO during catalytic transfer hydrogenations (CTH) of ketones using alcohols as hydrogen donors. Our previous studies showed that deactivation of MgO could be prevented by previous treatment with chloromethanes. Therefore the surface species formed during the reaction were studied before and after treatment with chloroform or chloroform-d by in situ infrared spectroscopy (IR). As a result, it was concluded that the reaction requires the presence of surface basic andacidic centers. The presence of Lewis acid centers was not necessary, the reaction could proceed on weakly acidic surface Bronsted sites, as the alterations in intensity and position of the v(OH) bands indicated. Modification with chloroform resulted also in the generation of surface OH groups with a proper acidity for the reaction. The shift in carbonyl vibrations led us to the conclusion that Lewis acid and base centers were responsible for the catalyst poisoning, so covering these acid sites by Cl- led to a stable catalyst.

KW - 2-Butanone

KW - 2-Propanol

KW - Active centers

KW - Chloroform

KW - Chloroform- d

KW - FT-IR spectroscopy

KW - Magnesium oxide

KW - Surface species

UR - http://www.scopus.com/inward/record.url?scp=0344603563&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0344603563&partnerID=8YFLogxK

U2 - 10.1016/S0022-2860(98)00833-3

DO - 10.1016/S0022-2860(98)00833-3

M3 - Article

AN - SCOPUS:0344603563

VL - 482-483

SP - 13

EP - 17

JO - Journal of Molecular Structure

JF - Journal of Molecular Structure

SN - 0022-2860

ER -