Effects of hydrogen on heptane isomerization over zirconium oxide modified with tungsten oxide and platinum

Muneeb Khurshid; Mohammed A. Al-Daous; Hideshi Hattori; Sulaiman S. Al-Khattaf

doi:10.1016/j.apcata.2009.04.020

Effects of hydrogen on heptane isomerization over zirconium oxide modified with tungsten oxide and platinum

Muneeb Khurshid, Mohammed A. Al-Daous, Hideshi Hattori, Sulaiman S. Al-Khattaf^*

^*Corresponding author for this work

King Fahd University of Petroleum & Minerals

Research output: Contribution to journal › Article › peer-review

39 Scopus citations

Abstract

Heptane isomerization was carried out over Pt/WO₃-ZrO₂ under a hydrogen pressure range 0-2 MPa to elucidate the effects of hydrogen on the activity and selectivity of the catalyst. Optimum catalyst was prepared by calcination of WO₃-ZrO₂ at 1053 K and loading of 0.75 wt% of Pt with a constant WO₃ content of 11 wt%. The rate of isomerization was slightly negative in hydrogen pressure in a high pressure range (>0.3 MPa) and positive in a low pressure range (<0.3 MPa). Cracking was markedly suppressed in the reaction under a high hydrogen pressure, which is caused by a high concentration of hydride ion species on the surface. Hydride ions originating from hydrogen molecules play a key role in selective isomerization of heptane. Hydride transfer step was suggested to be slow as compared to skeletal rearrangement among mono- and di-branched carbenium ion intermediates. By controlling the reaction conditions, a high isomerization selectivity of 94% at a conversion of 80% was obtained at 553 K under a hydrogen pressure of 1.55 MPa.

Original language	English
Pages (from-to)	75-81
Number of pages	7
Journal	Applied Catalysis A: General
Volume	362
Issue number	1-2
DOIs	https://doi.org/10.1016/j.apcata.2009.04.020
State	Published - 30 Jun 2009

Bibliographical note

Funding Information:
We are grateful to the support from the Ministry of Higher Education, Saudi Arabia in establishment of the Center of Research Excellence in Petroleum Refining and Petrochemicals at King Fahd University of Petroleum and Minerals (KFUPM). We acknowledge Mr. Khurshid Alam for his assistance in experimental works. H.H. thanks the Japan Corporation Center, Petroleum for financial support.

Keywords

Heptane isomerization
Hydride ion species
Hydrogen effect
Solid acid
Zirconium oxide modified with platinum and tungsten oxide (Pt/WO-ZrO)

ASJC Scopus subject areas

Catalysis
Process Chemistry and Technology

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10.1016/j.apcata.2009.04.020

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title = "Effects of hydrogen on heptane isomerization over zirconium oxide modified with tungsten oxide and platinum",

abstract = "Heptane isomerization was carried out over Pt/WO3-ZrO2 under a hydrogen pressure range 0-2 MPa to elucidate the effects of hydrogen on the activity and selectivity of the catalyst. Optimum catalyst was prepared by calcination of WO3-ZrO2 at 1053 K and loading of 0.75 wt\% of Pt with a constant WO3 content of 11 wt\%. The rate of isomerization was slightly negative in hydrogen pressure in a high pressure range (>0.3 MPa) and positive in a low pressure range (<0.3 MPa). Cracking was markedly suppressed in the reaction under a high hydrogen pressure, which is caused by a high concentration of hydride ion species on the surface. Hydride ions originating from hydrogen molecules play a key role in selective isomerization of heptane. Hydride transfer step was suggested to be slow as compared to skeletal rearrangement among mono- and di-branched carbenium ion intermediates. By controlling the reaction conditions, a high isomerization selectivity of 94\% at a conversion of 80\% was obtained at 553 K under a hydrogen pressure of 1.55 MPa.",

keywords = "Heptane isomerization, Hydride ion species, Hydrogen effect, Solid acid, Zirconium oxide modified with platinum and tungsten oxide (Pt/WO-ZrO)",

author = "Muneeb Khurshid and Al-Daous, \{Mohammed A.\} and Hideshi Hattori and Al-Khattaf, \{Sulaiman S.\}",

note = "Funding Information: We are grateful to the support from the Ministry of Higher Education, Saudi Arabia in establishment of the Center of Research Excellence in Petroleum Refining and Petrochemicals at King Fahd University of Petroleum and Minerals (KFUPM). We acknowledge Mr. Khurshid Alam for his assistance in experimental works. H.H. thanks the Japan Corporation Center, Petroleum for financial support.",

year = "2009",

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doi = "10.1016/j.apcata.2009.04.020",

language = "English",

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pages = "75--81",

journal = "Applied Catalysis A: General",

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T1 - Effects of hydrogen on heptane isomerization over zirconium oxide modified with tungsten oxide and platinum

AU - Khurshid, Muneeb

AU - Al-Daous, Mohammed A.

AU - Hattori, Hideshi

AU - Al-Khattaf, Sulaiman S.

N1 - Funding Information: We are grateful to the support from the Ministry of Higher Education, Saudi Arabia in establishment of the Center of Research Excellence in Petroleum Refining and Petrochemicals at King Fahd University of Petroleum and Minerals (KFUPM). We acknowledge Mr. Khurshid Alam for his assistance in experimental works. H.H. thanks the Japan Corporation Center, Petroleum for financial support.

PY - 2009/6/30

Y1 - 2009/6/30

N2 - Heptane isomerization was carried out over Pt/WO3-ZrO2 under a hydrogen pressure range 0-2 MPa to elucidate the effects of hydrogen on the activity and selectivity of the catalyst. Optimum catalyst was prepared by calcination of WO3-ZrO2 at 1053 K and loading of 0.75 wt% of Pt with a constant WO3 content of 11 wt%. The rate of isomerization was slightly negative in hydrogen pressure in a high pressure range (>0.3 MPa) and positive in a low pressure range (<0.3 MPa). Cracking was markedly suppressed in the reaction under a high hydrogen pressure, which is caused by a high concentration of hydride ion species on the surface. Hydride ions originating from hydrogen molecules play a key role in selective isomerization of heptane. Hydride transfer step was suggested to be slow as compared to skeletal rearrangement among mono- and di-branched carbenium ion intermediates. By controlling the reaction conditions, a high isomerization selectivity of 94% at a conversion of 80% was obtained at 553 K under a hydrogen pressure of 1.55 MPa.

AB - Heptane isomerization was carried out over Pt/WO3-ZrO2 under a hydrogen pressure range 0-2 MPa to elucidate the effects of hydrogen on the activity and selectivity of the catalyst. Optimum catalyst was prepared by calcination of WO3-ZrO2 at 1053 K and loading of 0.75 wt% of Pt with a constant WO3 content of 11 wt%. The rate of isomerization was slightly negative in hydrogen pressure in a high pressure range (>0.3 MPa) and positive in a low pressure range (<0.3 MPa). Cracking was markedly suppressed in the reaction under a high hydrogen pressure, which is caused by a high concentration of hydride ion species on the surface. Hydride ions originating from hydrogen molecules play a key role in selective isomerization of heptane. Hydride transfer step was suggested to be slow as compared to skeletal rearrangement among mono- and di-branched carbenium ion intermediates. By controlling the reaction conditions, a high isomerization selectivity of 94% at a conversion of 80% was obtained at 553 K under a hydrogen pressure of 1.55 MPa.

KW - Heptane isomerization

KW - Hydride ion species

KW - Hydrogen effect

KW - Solid acid

KW - Zirconium oxide modified with platinum and tungsten oxide (Pt/WO-ZrO)

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DO - 10.1016/j.apcata.2009.04.020

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SN - 0926-860X

VL - 362

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JO - Applied Catalysis A: General

JF - Applied Catalysis A: General

IS - 1-2

ER -

Effects of hydrogen on heptane isomerization over zirconium oxide modified with tungsten oxide and platinum

Abstract

Bibliographical note

Keywords

ASJC Scopus subject areas

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