Effect of medium-temperature pretreatment on the active site distribution of Pt-, Pd- and Rh-graphimet

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

In order to obtain more information about the structure of transition metal-graphite intercalation compounds, we have studied the active site distribution of Pt-, Pd- and Rh-graphimet before and after medium-temperature pretreatment (MTR, 573 K, 1 h). The surface characterization was performed by 1-butene titration in a flow reactor system. The single turnover method enabled us to distinguish between direct and two-step hydrogenation sites, and isomerization centres. MTR causes a pronounced effect on the active site distribution of all the samples. For Pd- and Rh-graphimet, the decreased number of isomerization and hydrogenation sites observed after MTR is attributed to encapsulation of surface metal into graphite or formation of surface carbon deposits. Pt-graphimet, on the other hand, displays an increased number of active centres following MTR, which make its site distribution similar to that of supported platinum catalysts. The structural change observed may be due to the joint effect of interlayer platinum migration and recrystallization of surface platinum particles.

Original languageEnglish
Pages (from-to)899-901
Number of pages3
JournalJournal of Physics and Chemistry of Solids
Volume57
Issue number6-8
DOIs
Publication statusPublished - Jun 1996

Fingerprint

pretreatment
platinum
Platinum
isomerization
hydrogenation
graphite
Isomerization
Hydrogenation
butenes
intercalation
titration
Intercalation compounds
Temperature
metal surfaces
temperature
Graphite
interlayers
transition metals
Butenes
Titration

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

Cite this

@article{0eae08584a574652bff7dc573f4027ae,
title = "Effect of medium-temperature pretreatment on the active site distribution of Pt-, Pd- and Rh-graphimet",
abstract = "In order to obtain more information about the structure of transition metal-graphite intercalation compounds, we have studied the active site distribution of Pt-, Pd- and Rh-graphimet before and after medium-temperature pretreatment (MTR, 573 K, 1 h). The surface characterization was performed by 1-butene titration in a flow reactor system. The single turnover method enabled us to distinguish between direct and two-step hydrogenation sites, and isomerization centres. MTR causes a pronounced effect on the active site distribution of all the samples. For Pd- and Rh-graphimet, the decreased number of isomerization and hydrogenation sites observed after MTR is attributed to encapsulation of surface metal into graphite or formation of surface carbon deposits. Pt-graphimet, on the other hand, displays an increased number of active centres following MTR, which make its site distribution similar to that of supported platinum catalysts. The structural change observed may be due to the joint effect of interlayer platinum migration and recrystallization of surface platinum particles.",
author = "A. Mastalir and F. Notheisz and M. Bart{\'o}k",
year = "1996",
month = "6",
doi = "10.1016/0022-3697(95)00370-3",
language = "English",
volume = "57",
pages = "899--901",
journal = "Journal of Physics and Chemistry of Solids",
issn = "0022-3697",
publisher = "Elsevier Limited",
number = "6-8",

}

TY - JOUR

T1 - Effect of medium-temperature pretreatment on the active site distribution of Pt-, Pd- and Rh-graphimet

AU - Mastalir, A.

AU - Notheisz, F.

AU - Bartók, M.

PY - 1996/6

Y1 - 1996/6

N2 - In order to obtain more information about the structure of transition metal-graphite intercalation compounds, we have studied the active site distribution of Pt-, Pd- and Rh-graphimet before and after medium-temperature pretreatment (MTR, 573 K, 1 h). The surface characterization was performed by 1-butene titration in a flow reactor system. The single turnover method enabled us to distinguish between direct and two-step hydrogenation sites, and isomerization centres. MTR causes a pronounced effect on the active site distribution of all the samples. For Pd- and Rh-graphimet, the decreased number of isomerization and hydrogenation sites observed after MTR is attributed to encapsulation of surface metal into graphite or formation of surface carbon deposits. Pt-graphimet, on the other hand, displays an increased number of active centres following MTR, which make its site distribution similar to that of supported platinum catalysts. The structural change observed may be due to the joint effect of interlayer platinum migration and recrystallization of surface platinum particles.

AB - In order to obtain more information about the structure of transition metal-graphite intercalation compounds, we have studied the active site distribution of Pt-, Pd- and Rh-graphimet before and after medium-temperature pretreatment (MTR, 573 K, 1 h). The surface characterization was performed by 1-butene titration in a flow reactor system. The single turnover method enabled us to distinguish between direct and two-step hydrogenation sites, and isomerization centres. MTR causes a pronounced effect on the active site distribution of all the samples. For Pd- and Rh-graphimet, the decreased number of isomerization and hydrogenation sites observed after MTR is attributed to encapsulation of surface metal into graphite or formation of surface carbon deposits. Pt-graphimet, on the other hand, displays an increased number of active centres following MTR, which make its site distribution similar to that of supported platinum catalysts. The structural change observed may be due to the joint effect of interlayer platinum migration and recrystallization of surface platinum particles.

UR - http://www.scopus.com/inward/record.url?scp=0030164703&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0030164703&partnerID=8YFLogxK

U2 - 10.1016/0022-3697(95)00370-3

DO - 10.1016/0022-3697(95)00370-3

M3 - Article

VL - 57

SP - 899

EP - 901

JO - Journal of Physics and Chemistry of Solids

JF - Journal of Physics and Chemistry of Solids

SN - 0022-3697

IS - 6-8

ER -