In Situ Structure‐Function Studies of Oxide Supported Rhodium Catalysts by Combined Energy Dispersive XAFS and DRIFTS Spectroscopies

John Evans; Andrew J. Dent; Sofia Diaz-moreno; Steven G. Fiddy; Bhrat Jyoti; Mark A. Newton; Moniek Tromp

doi:10.1063/1.2644606

In Situ Structure‐Function Studies of Oxide Supported Rhodium Catalysts by Combined Energy Dispersive XAFS and DRIFTS Spectroscopies

John Evans^*, Andrew J. Dent, Sofia Diaz-moreno, Steven G. Fiddy, Bhrat Jyoti, Mark A. Newton, Moniek Tromp

^*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution › Academic › peer-review

3 Citations (Scopus)

Abstract

The techniques of energy dispersive EXAFS (EDE), diffuse reflectance Fourier transform infrared spectroscopy (DRIFTS) and mass spectrometry (MS) have been combined to study the structure and function of an oxide supported metal catalyst, namely 5 wt% Rh/Al₂O₃. Using a FreLoN camera as the EDE detector and a rapid-scanning IR spectrometer, experiments could be performed with a repetition rate of 50 ms. The results show that the nature of the rhodium centers is a function of the partial pressures of the reacting gases (CO and NO) and also temperature. This combination of gases oxidizes metallic rhodium particles to Rh(CO)₂ at room temperature. The proportion of the rhodium adopting this site increases as the temperature is raised (up to 450 K). Above that temperature the dicarbonyl decomposes and the metal reclusters. Once this condition is met, catalysis ensues. Gas switching techniques show that at 573 K with NO in excess, the clusters can be oxidized rapidly to afford a linear nitrosyl complex; re-exposure to CO also promotes reclustering and the CO adopts terminal (atop) and bridging (2-fold) sites.

Original language	English
Title of host publication	X-RAY ABSORPTION FINE STRUCTURE - XAFS13
Subtitle of host publication	13th International Conference
Publisher	AIP PRESS
Pages	603-607
Number of pages	5
ISBN (Print)	9780735403840
DOIs	https://doi.org/10.1063/1.2644606
Publication status	Published - 27-Mar-2007
Externally published	Yes
Event	X-RAY ABSORPTION FINE STRUCTURE - XAFS13: 13th International Conference - Stanford, CA, United States Duration: 9-Jul-2006 → 14-Jul-2006

Publication series

Name	AIP Conference Proceedings
Volume	882
ISSN (Print)	0094-243X
ISSN (Electronic)	1551-7616

Conference

Conference	X-RAY ABSORPTION FINE STRUCTURE - XAFS13: 13th International Conference
Country/Territory	United States
City	Stanford, CA
Period	09/07/2006 → 14/07/2006

Keywords

Catalysis
IR
Rhodium
XAFS

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Evans, J., Dent, A. J., Diaz-moreno, S., Fiddy, S. G., Jyoti, B., Newton, M. A., & Tromp, M. (2007). In Situ Structure‐Function Studies of Oxide Supported Rhodium Catalysts by Combined Energy Dispersive XAFS and DRIFTS Spectroscopies. In X-RAY ABSORPTION FINE STRUCTURE - XAFS13: 13th International Conference (pp. 603-607). (AIP Conference Proceedings; Vol. 882). AIP PRESS. https://doi.org/10.1063/1.2644606

@inproceedings{da6fa1ec66dc40099b768db5ea14b089,

title = "In Situ Structure‐Function Studies of Oxide Supported Rhodium Catalysts by Combined Energy Dispersive XAFS and DRIFTS Spectroscopies",

abstract = "The techniques of energy dispersive EXAFS (EDE), diffuse reflectance Fourier transform infrared spectroscopy (DRIFTS) and mass spectrometry (MS) have been combined to study the structure and function of an oxide supported metal catalyst, namely 5 wt% Rh/Al2O3. Using a FreLoN camera as the EDE detector and a rapid-scanning IR spectrometer, experiments could be performed with a repetition rate of 50 ms. The results show that the nature of the rhodium centers is a function of the partial pressures of the reacting gases (CO and NO) and also temperature. This combination of gases oxidizes metallic rhodium particles to Rh(CO)2 at room temperature. The proportion of the rhodium adopting this site increases as the temperature is raised (up to 450 K). Above that temperature the dicarbonyl decomposes and the metal reclusters. Once this condition is met, catalysis ensues. Gas switching techniques show that at 573 K with NO in excess, the clusters can be oxidized rapidly to afford a linear nitrosyl complex; re-exposure to CO also promotes reclustering and the CO adopts terminal (atop) and bridging (2-fold) sites.",

keywords = "Catalysis, IR, Rhodium, XAFS",

author = "John Evans and Dent, {Andrew J.} and Sofia Diaz-moreno and Fiddy, {Steven G.} and Bhrat Jyoti and Newton, {Mark A.} and Moniek Tromp",

year = "2007",

month = mar,

day = "27",

doi = "10.1063/1.2644606",

language = "English",

isbn = "9780735403840",

series = "AIP Conference Proceedings",

publisher = "AIP PRESS",

pages = "603--607",

booktitle = "X-RAY ABSORPTION FINE STRUCTURE - XAFS13",

note = "X-RAY ABSORPTION FINE STRUCTURE - XAFS13: 13th International Conference ; Conference date: 09-07-2006 Through 14-07-2006",

}

Evans, J, Dent, AJ, Diaz-moreno, S, Fiddy, SG, Jyoti, B, Newton, MA & Tromp, M 2007, In Situ Structure‐Function Studies of Oxide Supported Rhodium Catalysts by Combined Energy Dispersive XAFS and DRIFTS Spectroscopies. in X-RAY ABSORPTION FINE STRUCTURE - XAFS13: 13th International Conference. AIP Conference Proceedings, vol. 882, AIP PRESS, pp. 603-607, X-RAY ABSORPTION FINE STRUCTURE - XAFS13: 13th International Conference, Stanford, CA, United States, 09/07/2006. https://doi.org/10.1063/1.2644606

In Situ Structure‐Function Studies of Oxide Supported Rhodium Catalysts by Combined Energy Dispersive XAFS and DRIFTS Spectroscopies. / Evans, John; Dent, Andrew J.; Diaz-moreno, Sofia et al.
X-RAY ABSORPTION FINE STRUCTURE - XAFS13: 13th International Conference. AIP PRESS, 2007. p. 603-607 (AIP Conference Proceedings; Vol. 882).

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution › Academic › peer-review

TY - GEN

T1 - In Situ Structure‐Function Studies of Oxide Supported Rhodium Catalysts by Combined Energy Dispersive XAFS and DRIFTS Spectroscopies

AU - Evans, John

AU - Dent, Andrew J.

AU - Diaz-moreno, Sofia

AU - Fiddy, Steven G.

AU - Jyoti, Bhrat

AU - Newton, Mark A.

AU - Tromp, Moniek

PY - 2007/3/27

Y1 - 2007/3/27

N2 - The techniques of energy dispersive EXAFS (EDE), diffuse reflectance Fourier transform infrared spectroscopy (DRIFTS) and mass spectrometry (MS) have been combined to study the structure and function of an oxide supported metal catalyst, namely 5 wt% Rh/Al2O3. Using a FreLoN camera as the EDE detector and a rapid-scanning IR spectrometer, experiments could be performed with a repetition rate of 50 ms. The results show that the nature of the rhodium centers is a function of the partial pressures of the reacting gases (CO and NO) and also temperature. This combination of gases oxidizes metallic rhodium particles to Rh(CO)2 at room temperature. The proportion of the rhodium adopting this site increases as the temperature is raised (up to 450 K). Above that temperature the dicarbonyl decomposes and the metal reclusters. Once this condition is met, catalysis ensues. Gas switching techniques show that at 573 K with NO in excess, the clusters can be oxidized rapidly to afford a linear nitrosyl complex; re-exposure to CO also promotes reclustering and the CO adopts terminal (atop) and bridging (2-fold) sites.

AB - The techniques of energy dispersive EXAFS (EDE), diffuse reflectance Fourier transform infrared spectroscopy (DRIFTS) and mass spectrometry (MS) have been combined to study the structure and function of an oxide supported metal catalyst, namely 5 wt% Rh/Al2O3. Using a FreLoN camera as the EDE detector and a rapid-scanning IR spectrometer, experiments could be performed with a repetition rate of 50 ms. The results show that the nature of the rhodium centers is a function of the partial pressures of the reacting gases (CO and NO) and also temperature. This combination of gases oxidizes metallic rhodium particles to Rh(CO)2 at room temperature. The proportion of the rhodium adopting this site increases as the temperature is raised (up to 450 K). Above that temperature the dicarbonyl decomposes and the metal reclusters. Once this condition is met, catalysis ensues. Gas switching techniques show that at 573 K with NO in excess, the clusters can be oxidized rapidly to afford a linear nitrosyl complex; re-exposure to CO also promotes reclustering and the CO adopts terminal (atop) and bridging (2-fold) sites.

KW - Catalysis

KW - IR

KW - Rhodium

KW - XAFS

UR - http://www.scopus.com/inward/record.url?scp=33947431658&partnerID=8YFLogxK

U2 - 10.1063/1.2644606

DO - 10.1063/1.2644606

M3 - Conference contribution

AN - SCOPUS:33947431658

SN - 9780735403840

T3 - AIP Conference Proceedings

SP - 603

EP - 607

BT - X-RAY ABSORPTION FINE STRUCTURE - XAFS13

PB - AIP PRESS

T2 - X-RAY ABSORPTION FINE STRUCTURE - XAFS13: 13th International Conference

Y2 - 9 July 2006 through 14 July 2006

ER -

In Situ Structure‐Function Studies of Oxide Supported Rhodium Catalysts by Combined Energy Dispersive XAFS and DRIFTS Spectroscopies

Abstract

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Keywords

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