Effect of Alumina Phase Transformation on Stability of Low-Loaded Pd-Rh Catalysts for CO Oxidation

Aleksey A. Vedyagin, Alexander M. Volodin, Vladimir O. Stoyanovskii, Roman M. Kenzhin, Pavel E. Plyusnin, Yury V. Shubin, Ilya V. Mishakov

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

Bimetallic Pd-Rh catalysts with precious metal loading of 0.2 wt% was prepared by incipient wetness impregnation of the support (γ-Al2O3 or δ-Al2O3) with dual complex salt [Pd(NH3)4]3 [Rh(NO2)6]2. Monometallic Pd and Rh catalysts as well as its mechanical mixture were used as the reference samples. All samples were exposed for in situ prompt thermal aging procedure, and characterized by EPR spectroscopy, UV–Vis diffuse reflectance spectroscopy and photoluminescence spectroscopy. The nature of the support was found to have strong effect on high temperature stability of the samples. δ-Al2O3 having non-uniform phase structure due to presence of θ-Al2O3 and α-Al2O3 traces causes the concentrating of rhodium near the interphase boundary, thus changing the mechanism of Rh3+ bulk diffusion if compare with γ-Al2O3. No noticeable anchoring effects were observed for bimetallic Pd-Rh samples neither in terms of Rh bulk diffusion nor with regard to the Pd sintering. It has been found experimentally that phase transformation of γ-Al2O3 at high temperatures does not play dramatic role for the deactivation of bimetallic Pd-Rh active species anchored to the electron-donor site of the support.

Original languageEnglish
Pages (from-to)152-161
Number of pages10
JournalTopics in Catalysis
Volume60
Issue number1-2
DOIs
Publication statusPublished - 1 Feb 2017

Fingerprint

Aluminum Oxide
Carbon Monoxide
Alumina
Phase transitions
Spectroscopy
Oxidation
Rhodium
Catalysts
Thermal aging
Photoluminescence spectroscopy
Phase structure
Precious metals
Impregnation
Paramagnetic resonance
Sintering
Salts
Temperature
Electrons

Keywords

  • Alumina
  • Bimetallic Pd-Rh catalysts
  • CO oxidation
  • Deactivation
  • Phase transformation
  • Stability
  • Thermal aging

ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)

Cite this

Effect of Alumina Phase Transformation on Stability of Low-Loaded Pd-Rh Catalysts for CO Oxidation. / Vedyagin, Aleksey A.; Volodin, Alexander M.; Stoyanovskii, Vladimir O.; Kenzhin, Roman M.; Plyusnin, Pavel E.; Shubin, Yury V.; Mishakov, Ilya V.

In: Topics in Catalysis, Vol. 60, No. 1-2, 01.02.2017, p. 152-161.

Research output: Contribution to journalArticle

Vedyagin, Aleksey A. ; Volodin, Alexander M. ; Stoyanovskii, Vladimir O. ; Kenzhin, Roman M. ; Plyusnin, Pavel E. ; Shubin, Yury V. ; Mishakov, Ilya V. / Effect of Alumina Phase Transformation on Stability of Low-Loaded Pd-Rh Catalysts for CO Oxidation. In: Topics in Catalysis. 2017 ; Vol. 60, No. 1-2. pp. 152-161.
@article{34ee8a6480f1439187be0424f92a83a6,
title = "Effect of Alumina Phase Transformation on Stability of Low-Loaded Pd-Rh Catalysts for CO Oxidation",
abstract = "Bimetallic Pd-Rh catalysts with precious metal loading of 0.2 wt{\%} was prepared by incipient wetness impregnation of the support (γ-Al2O3 or δ-Al2O3) with dual complex salt [Pd(NH3)4]3 [Rh(NO2)6]2. Monometallic Pd and Rh catalysts as well as its mechanical mixture were used as the reference samples. All samples were exposed for in situ prompt thermal aging procedure, and characterized by EPR spectroscopy, UV–Vis diffuse reflectance spectroscopy and photoluminescence spectroscopy. The nature of the support was found to have strong effect on high temperature stability of the samples. δ-Al2O3 having non-uniform phase structure due to presence of θ-Al2O3 and α-Al2O3 traces causes the concentrating of rhodium near the interphase boundary, thus changing the mechanism of Rh3+ bulk diffusion if compare with γ-Al2O3. No noticeable anchoring effects were observed for bimetallic Pd-Rh samples neither in terms of Rh bulk diffusion nor with regard to the Pd sintering. It has been found experimentally that phase transformation of γ-Al2O3 at high temperatures does not play dramatic role for the deactivation of bimetallic Pd-Rh active species anchored to the electron-donor site of the support.",
keywords = "Alumina, Bimetallic Pd-Rh catalysts, CO oxidation, Deactivation, Phase transformation, Stability, Thermal aging",
author = "Vedyagin, {Aleksey A.} and Volodin, {Alexander M.} and Stoyanovskii, {Vladimir O.} and Kenzhin, {Roman M.} and Plyusnin, {Pavel E.} and Shubin, {Yury V.} and Mishakov, {Ilya V.}",
year = "2017",
month = "2",
day = "1",
doi = "10.1007/s11244-016-0726-4",
language = "English",
volume = "60",
pages = "152--161",
journal = "Topics in Catalysis",
issn = "1022-5528",
publisher = "Springer Netherlands",
number = "1-2",

}

TY - JOUR

T1 - Effect of Alumina Phase Transformation on Stability of Low-Loaded Pd-Rh Catalysts for CO Oxidation

AU - Vedyagin, Aleksey A.

AU - Volodin, Alexander M.

AU - Stoyanovskii, Vladimir O.

AU - Kenzhin, Roman M.

AU - Plyusnin, Pavel E.

AU - Shubin, Yury V.

AU - Mishakov, Ilya V.

PY - 2017/2/1

Y1 - 2017/2/1

N2 - Bimetallic Pd-Rh catalysts with precious metal loading of 0.2 wt% was prepared by incipient wetness impregnation of the support (γ-Al2O3 or δ-Al2O3) with dual complex salt [Pd(NH3)4]3 [Rh(NO2)6]2. Monometallic Pd and Rh catalysts as well as its mechanical mixture were used as the reference samples. All samples were exposed for in situ prompt thermal aging procedure, and characterized by EPR spectroscopy, UV–Vis diffuse reflectance spectroscopy and photoluminescence spectroscopy. The nature of the support was found to have strong effect on high temperature stability of the samples. δ-Al2O3 having non-uniform phase structure due to presence of θ-Al2O3 and α-Al2O3 traces causes the concentrating of rhodium near the interphase boundary, thus changing the mechanism of Rh3+ bulk diffusion if compare with γ-Al2O3. No noticeable anchoring effects were observed for bimetallic Pd-Rh samples neither in terms of Rh bulk diffusion nor with regard to the Pd sintering. It has been found experimentally that phase transformation of γ-Al2O3 at high temperatures does not play dramatic role for the deactivation of bimetallic Pd-Rh active species anchored to the electron-donor site of the support.

AB - Bimetallic Pd-Rh catalysts with precious metal loading of 0.2 wt% was prepared by incipient wetness impregnation of the support (γ-Al2O3 or δ-Al2O3) with dual complex salt [Pd(NH3)4]3 [Rh(NO2)6]2. Monometallic Pd and Rh catalysts as well as its mechanical mixture were used as the reference samples. All samples were exposed for in situ prompt thermal aging procedure, and characterized by EPR spectroscopy, UV–Vis diffuse reflectance spectroscopy and photoluminescence spectroscopy. The nature of the support was found to have strong effect on high temperature stability of the samples. δ-Al2O3 having non-uniform phase structure due to presence of θ-Al2O3 and α-Al2O3 traces causes the concentrating of rhodium near the interphase boundary, thus changing the mechanism of Rh3+ bulk diffusion if compare with γ-Al2O3. No noticeable anchoring effects were observed for bimetallic Pd-Rh samples neither in terms of Rh bulk diffusion nor with regard to the Pd sintering. It has been found experimentally that phase transformation of γ-Al2O3 at high temperatures does not play dramatic role for the deactivation of bimetallic Pd-Rh active species anchored to the electron-donor site of the support.

KW - Alumina

KW - Bimetallic Pd-Rh catalysts

KW - CO oxidation

KW - Deactivation

KW - Phase transformation

KW - Stability

KW - Thermal aging

UR - http://www.scopus.com/inward/record.url?scp=85013908893&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85013908893&partnerID=8YFLogxK

U2 - 10.1007/s11244-016-0726-4

DO - 10.1007/s11244-016-0726-4

M3 - Article

VL - 60

SP - 152

EP - 161

JO - Topics in Catalysis

JF - Topics in Catalysis

SN - 1022-5528

IS - 1-2

ER -