fulltext.study @t Gmail

Hydrogen spillover behavior of Zn/HZSM-5 showing catalytically active protonic acid sites in the isomerization of n-pentane

Paper ID Volume ID Publish Year Pages File Format Full-Text
41296 45884 2011 9 PDF Available
Title
Hydrogen spillover behavior of Zn/HZSM-5 showing catalytically active protonic acid sites in the isomerization of n-pentane
Abstract

The impregnation of zinc particles into MFI zeolite (HZSM-5) caused the formation of catalytically active protonic acid sites for isomerizing n-pentane in the presence of hydrogen. An infrared (IR) study with preadsorbed pyridine revealed that these protonic acid sites originated from the spillover of molecular hydrogen from the zinc species onto the zeolite surface. The requirements for this spillover effect were further studied by IR spectroscopy of adsorbed ammonia and carbon monoxide. The presence of zinc species in HZSM-5 suggested the exchange of acidic character towards strong Lewis acids rather than Brønsted acid sites. The isomerization of n-pentane over the Zn/HZSM-5 catalyst resulted in high activity and stability and the conversion to iso-pentane depends on the promotive effect of hydrogen as a carrier gas.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (200 K)Download as PowerPoint slideHighlights► Zn2+ exchanged the Brønsted acid sites to Lewis acid sites. ► Active protonic acid sites are formed from H2 via hydrogen spillover mechanism. ► Lewis acid sites and Zn species are indispensable in the formation of H+. ► The catalytic activity of Zn/HZSM-5 is strongly determined by the presence of H+. ► Low activity was observed on Zn-free HZSM-5 under H2 carrier gas.

Keywords
Zn/HZSM-5; Protonic acid sites; Lewis acid sites; Molecular hydrogen; n-Pentane isomerization
First Page Preview
Hydrogen spillover behavior of Zn/HZSM-5 showing catalytically active protonic acid sites in the isomerization of n-pentane
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us
Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis A: General - Volume 407, Issues 1–2, 4 November 2011, Pages 91–99
Authors
, , , , , ,
Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us