Reactions of methylcyclopentane on Rh-Pt catalyst prepared by underpotential deposition of Rh on Pt/SiO2

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Abstract

Rh was deposited on to a well-characterized 3.1% Pt/SiO2 (InCat-1) parent catalyst by underpotential deposition method to obtain a model Rh-Pt bimetallic catalyst. TEM and EDS was used to determine its mean particle size and bulk composition: the particles of ca. 3 nm contained ca. 60% Pt and 40% Rh. The Rh-Pt catalyst was tested in methylcyclopentane (MCP) reaction between 513 K and 603 K and 60-480 Torr H2 pressure (with 10 Torr MCP). The parent Pt/SiO2 as well as a 5% Rh/SiO2 catalyst were also studied for comparison. Four subsequent treatments with O2 and H2 up to T = 673 K were applied on the bimetallic catalyst before the catalytic runs. The overall activity showed positive hydrogen order on all samples, bimetallic Rh-Pt resulting in the lowest TOF values. Ring opening and hydrogenolysis products, as well as unsaturated hydrocarbons were formed from MCP. The selectivity of ring opening products and fragments over Rh-Pt catalyst was between the values observed on Pt and Rh, while the selectivity towards benzene formation was highest on the bimetallic sample, especially at higher temperatures. "Selective" ring opening occurred on all samples, resulting mostly in 2 and 3-methylpentane and less hexane. Different pretreatments with H2 and O2 affected slightly the dispersion values and the catalytic behavior of Rh-Pt sample. The selectivities of the Rh-Pt catalyst being between the values observed for Pt/SiO2 and Rh/SiO2 indicates that the sample studied represented a real bimetallic catalyst, resembling both components and exhibiting at the same time, new properties in addition to those, characteristic of Pt or Rh.

Original languageEnglish
Pages (from-to)57-64
Number of pages8
JournalTopics in Catalysis
Volume46
Issue number1-2
DOIs
Publication statusPublished - Sep 2007

Fingerprint

catalysts
Catalysts
selectivity
rings
hydrogenolysis
Hydrogenolysis
methylcyclopentane
Catalyst selectivity
Hexanes
products
Hydrocarbons
Benzene
Hexane
pretreatment
Energy dispersive spectroscopy
Hydrogen
hydrocarbons
Particle size
benzene
fragments

Keywords

  • Bimetallic catalyst
  • InCat-1
  • Methylcyclopentane ring opening
  • Platinum
  • Pt
  • Rh
  • Rhodium
  • Underpotential deposition

ASJC Scopus subject areas

  • Chemistry (miscellaneous)
  • Physical and Theoretical Chemistry
  • Catalysis

Cite this

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title = "Reactions of methylcyclopentane on Rh-Pt catalyst prepared by underpotential deposition of Rh on Pt/SiO2",
abstract = "Rh was deposited on to a well-characterized 3.1{\%} Pt/SiO2 (InCat-1) parent catalyst by underpotential deposition method to obtain a model Rh-Pt bimetallic catalyst. TEM and EDS was used to determine its mean particle size and bulk composition: the particles of ca. 3 nm contained ca. 60{\%} Pt and 40{\%} Rh. The Rh-Pt catalyst was tested in methylcyclopentane (MCP) reaction between 513 K and 603 K and 60-480 Torr H2 pressure (with 10 Torr MCP). The parent Pt/SiO2 as well as a 5{\%} Rh/SiO2 catalyst were also studied for comparison. Four subsequent treatments with O2 and H2 up to T = 673 K were applied on the bimetallic catalyst before the catalytic runs. The overall activity showed positive hydrogen order on all samples, bimetallic Rh-Pt resulting in the lowest TOF values. Ring opening and hydrogenolysis products, as well as unsaturated hydrocarbons were formed from MCP. The selectivity of ring opening products and fragments over Rh-Pt catalyst was between the values observed on Pt and Rh, while the selectivity towards benzene formation was highest on the bimetallic sample, especially at higher temperatures. {"}Selective{"} ring opening occurred on all samples, resulting mostly in 2 and 3-methylpentane and less hexane. Different pretreatments with H2 and O2 affected slightly the dispersion values and the catalytic behavior of Rh-Pt sample. The selectivities of the Rh-Pt catalyst being between the values observed for Pt/SiO2 and Rh/SiO2 indicates that the sample studied represented a real bimetallic catalyst, resembling both components and exhibiting at the same time, new properties in addition to those, characteristic of Pt or Rh.",
keywords = "Bimetallic catalyst, InCat-1, Methylcyclopentane ring opening, Platinum, Pt, Rh, Rhodium, Underpotential deposition",
author = "N{\'o}ra Gyorffy and A. Wootsch and S. Szab{\'o} and I. Bakos and L. T{\'o}th and Z. Pa{\'a}l",
year = "2007",
month = "9",
doi = "10.1007/s11244-007-0315-7",
language = "English",
volume = "46",
pages = "57--64",
journal = "Topics in Catalysis",
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T1 - Reactions of methylcyclopentane on Rh-Pt catalyst prepared by underpotential deposition of Rh on Pt/SiO2

AU - Gyorffy, Nóra

AU - Wootsch, A.

AU - Szabó, S.

AU - Bakos, I.

AU - Tóth, L.

AU - Paál, Z.

PY - 2007/9

Y1 - 2007/9

N2 - Rh was deposited on to a well-characterized 3.1% Pt/SiO2 (InCat-1) parent catalyst by underpotential deposition method to obtain a model Rh-Pt bimetallic catalyst. TEM and EDS was used to determine its mean particle size and bulk composition: the particles of ca. 3 nm contained ca. 60% Pt and 40% Rh. The Rh-Pt catalyst was tested in methylcyclopentane (MCP) reaction between 513 K and 603 K and 60-480 Torr H2 pressure (with 10 Torr MCP). The parent Pt/SiO2 as well as a 5% Rh/SiO2 catalyst were also studied for comparison. Four subsequent treatments with O2 and H2 up to T = 673 K were applied on the bimetallic catalyst before the catalytic runs. The overall activity showed positive hydrogen order on all samples, bimetallic Rh-Pt resulting in the lowest TOF values. Ring opening and hydrogenolysis products, as well as unsaturated hydrocarbons were formed from MCP. The selectivity of ring opening products and fragments over Rh-Pt catalyst was between the values observed on Pt and Rh, while the selectivity towards benzene formation was highest on the bimetallic sample, especially at higher temperatures. "Selective" ring opening occurred on all samples, resulting mostly in 2 and 3-methylpentane and less hexane. Different pretreatments with H2 and O2 affected slightly the dispersion values and the catalytic behavior of Rh-Pt sample. The selectivities of the Rh-Pt catalyst being between the values observed for Pt/SiO2 and Rh/SiO2 indicates that the sample studied represented a real bimetallic catalyst, resembling both components and exhibiting at the same time, new properties in addition to those, characteristic of Pt or Rh.

AB - Rh was deposited on to a well-characterized 3.1% Pt/SiO2 (InCat-1) parent catalyst by underpotential deposition method to obtain a model Rh-Pt bimetallic catalyst. TEM and EDS was used to determine its mean particle size and bulk composition: the particles of ca. 3 nm contained ca. 60% Pt and 40% Rh. The Rh-Pt catalyst was tested in methylcyclopentane (MCP) reaction between 513 K and 603 K and 60-480 Torr H2 pressure (with 10 Torr MCP). The parent Pt/SiO2 as well as a 5% Rh/SiO2 catalyst were also studied for comparison. Four subsequent treatments with O2 and H2 up to T = 673 K were applied on the bimetallic catalyst before the catalytic runs. The overall activity showed positive hydrogen order on all samples, bimetallic Rh-Pt resulting in the lowest TOF values. Ring opening and hydrogenolysis products, as well as unsaturated hydrocarbons were formed from MCP. The selectivity of ring opening products and fragments over Rh-Pt catalyst was between the values observed on Pt and Rh, while the selectivity towards benzene formation was highest on the bimetallic sample, especially at higher temperatures. "Selective" ring opening occurred on all samples, resulting mostly in 2 and 3-methylpentane and less hexane. Different pretreatments with H2 and O2 affected slightly the dispersion values and the catalytic behavior of Rh-Pt sample. The selectivities of the Rh-Pt catalyst being between the values observed for Pt/SiO2 and Rh/SiO2 indicates that the sample studied represented a real bimetallic catalyst, resembling both components and exhibiting at the same time, new properties in addition to those, characteristic of Pt or Rh.

KW - Bimetallic catalyst

KW - InCat-1

KW - Methylcyclopentane ring opening

KW - Platinum

KW - Pt

KW - Rh

KW - Rhodium

KW - Underpotential deposition

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U2 - 10.1007/s11244-007-0315-7

DO - 10.1007/s11244-007-0315-7

M3 - Article

VL - 46

SP - 57

EP - 64

JO - Topics in Catalysis

JF - Topics in Catalysis

SN - 1022-5528

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