Infrared spectroscopic study of the adsorption and reactions of CO2 on K-modified Rh/SiO2

F. Solymosi, Helmut Knozinger

Research output: Contribution to journalArticle

60 Citations (Scopus)

Abstract

Adsorption of CO2 on K-free Rh/SiO2 at 140 K produced only a strong band at 2340 cm-1 characteristic of weakly bonded CO2. There was no carbonate formation and CO2 desorbed completely from this surface below 250 K without any detectable dissociation. Co-adsorption of H2 + CO2 on Rh/SiO2 led to the formation of CO bands at 2050 and 2015 cm-1, indicating the dissociation of CO2. Formate bands were not observed. Adsorption of CO2 on K-modified Rh/SiO2 produced an intense band at 1695-1675 cm-1 and a weak band at 1325-1360 cm-1, which are attributed to the formation of CO2- anions bonded to K+ ions. Spectral changes observed above 200 K suggest that this species is transformed into bidentate carbonate characterized by absorption bands at 1660, 1525, and 1360 cm-1. As the same features were observed for Rh-free samples, it was concluded that both species are coordinated to K+-sites on the silica surface. CO2- reacted with hydrogen on (K + Rh)/SiO2 to give formate at temperatures as low as 150 K. No formate was produced on K/SiO2 in the absence of Rh.

Original languageEnglish
Pages (from-to)166-177
Number of pages12
JournalJournal of Catalysis
Volume122
Issue number1
DOIs
Publication statusPublished - 1990

Fingerprint

formic acid
Carbonates
Infrared radiation
formates
Adsorption
adsorption
Carbon Monoxide
carbonates
Silicon Dioxide
Anions
Absorption spectra
Hydrogen
dissociation
Negative ions
Silica
Ions
silicon dioxide
anions
absorption spectra

ASJC Scopus subject areas

  • Catalysis
  • Process Chemistry and Technology

Cite this

Infrared spectroscopic study of the adsorption and reactions of CO2 on K-modified Rh/SiO2. / Solymosi, F.; Knozinger, Helmut.

In: Journal of Catalysis, Vol. 122, No. 1, 1990, p. 166-177.

Research output: Contribution to journalArticle

@article{362d973723eb4bbba3c6c3531e20ae9a,
title = "Infrared spectroscopic study of the adsorption and reactions of CO2 on K-modified Rh/SiO2",
abstract = "Adsorption of CO2 on K-free Rh/SiO2 at 140 K produced only a strong band at 2340 cm-1 characteristic of weakly bonded CO2. There was no carbonate formation and CO2 desorbed completely from this surface below 250 K without any detectable dissociation. Co-adsorption of H2 + CO2 on Rh/SiO2 led to the formation of CO bands at 2050 and 2015 cm-1, indicating the dissociation of CO2. Formate bands were not observed. Adsorption of CO2 on K-modified Rh/SiO2 produced an intense band at 1695-1675 cm-1 and a weak band at 1325-1360 cm-1, which are attributed to the formation of CO2- anions bonded to K+ ions. Spectral changes observed above 200 K suggest that this species is transformed into bidentate carbonate characterized by absorption bands at 1660, 1525, and 1360 cm-1. As the same features were observed for Rh-free samples, it was concluded that both species are coordinated to K+-sites on the silica surface. CO2- reacted with hydrogen on (K + Rh)/SiO2 to give formate at temperatures as low as 150 K. No formate was produced on K/SiO2 in the absence of Rh.",
author = "F. Solymosi and Helmut Knozinger",
year = "1990",
doi = "10.1016/0021-9517(90)90268-O",
language = "English",
volume = "122",
pages = "166--177",
journal = "Journal of Catalysis",
issn = "0021-9517",
publisher = "Academic Press Inc.",
number = "1",

}

TY - JOUR

T1 - Infrared spectroscopic study of the adsorption and reactions of CO2 on K-modified Rh/SiO2

AU - Solymosi, F.

AU - Knozinger, Helmut

PY - 1990

Y1 - 1990

N2 - Adsorption of CO2 on K-free Rh/SiO2 at 140 K produced only a strong band at 2340 cm-1 characteristic of weakly bonded CO2. There was no carbonate formation and CO2 desorbed completely from this surface below 250 K without any detectable dissociation. Co-adsorption of H2 + CO2 on Rh/SiO2 led to the formation of CO bands at 2050 and 2015 cm-1, indicating the dissociation of CO2. Formate bands were not observed. Adsorption of CO2 on K-modified Rh/SiO2 produced an intense band at 1695-1675 cm-1 and a weak band at 1325-1360 cm-1, which are attributed to the formation of CO2- anions bonded to K+ ions. Spectral changes observed above 200 K suggest that this species is transformed into bidentate carbonate characterized by absorption bands at 1660, 1525, and 1360 cm-1. As the same features were observed for Rh-free samples, it was concluded that both species are coordinated to K+-sites on the silica surface. CO2- reacted with hydrogen on (K + Rh)/SiO2 to give formate at temperatures as low as 150 K. No formate was produced on K/SiO2 in the absence of Rh.

AB - Adsorption of CO2 on K-free Rh/SiO2 at 140 K produced only a strong band at 2340 cm-1 characteristic of weakly bonded CO2. There was no carbonate formation and CO2 desorbed completely from this surface below 250 K without any detectable dissociation. Co-adsorption of H2 + CO2 on Rh/SiO2 led to the formation of CO bands at 2050 and 2015 cm-1, indicating the dissociation of CO2. Formate bands were not observed. Adsorption of CO2 on K-modified Rh/SiO2 produced an intense band at 1695-1675 cm-1 and a weak band at 1325-1360 cm-1, which are attributed to the formation of CO2- anions bonded to K+ ions. Spectral changes observed above 200 K suggest that this species is transformed into bidentate carbonate characterized by absorption bands at 1660, 1525, and 1360 cm-1. As the same features were observed for Rh-free samples, it was concluded that both species are coordinated to K+-sites on the silica surface. CO2- reacted with hydrogen on (K + Rh)/SiO2 to give formate at temperatures as low as 150 K. No formate was produced on K/SiO2 in the absence of Rh.

UR - http://www.scopus.com/inward/record.url?scp=0000286989&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0000286989&partnerID=8YFLogxK

U2 - 10.1016/0021-9517(90)90268-O

DO - 10.1016/0021-9517(90)90268-O

M3 - Article

AN - SCOPUS:0000286989

VL - 122

SP - 166

EP - 177

JO - Journal of Catalysis

JF - Journal of Catalysis

SN - 0021-9517

IS - 1

ER -