fulltext.study @t Gmail

Ceria and lanthana as blocking modifiers for the external surface of MFI zeolite

Paper ID Volume ID Publish Year Pages File Format Full-Text
39777 45835 2014 11 PDF Available
Title
Ceria and lanthana as blocking modifiers for the external surface of MFI zeolite
Abstract

•Ceria and lanthana were differently impregnated on MFI.•Ceria was mainly dispersed on the external surface of MFI.•Dispersed ceria preserved the catalytic activity of MFI in MTO.•Lanthana intruded into the pores of MFI and lowered its acidity and pore volume.•The segregation of ceria particles prevented its intrusion into pores.

The ceria- and lanthana-modified MFI zeolites were prepared and extensively investigated to verify the function of lanthanide oxides as blocking modifiers. Their catalytic behavior in the methanol-to-olefin (MTO) conversion was explained by the characterization results regarding crystallinity, agglomeration, porosity, surface composition, and the uptakes of o-xylene and methanol. The ceria impregnated on the MFI formed nano-sized small particles with two oxidation states of +3 and +4 (Ce2O3 and CeO2) on the surface and was located predominantly on the external surface. So, the ceria impregnation maintained the porosity and activity of the MFI, and induced little change in the conversion and product composition of MTO. However, the lanthana impregnated on the MFI dispersed as a single lanthana (La2O3) phase in its micropores, as well as on the external surface. The blocking of the micropores and reduction of acidity by lanthana impregnation lowered the activity of the lanthana-modified MFI in MTO. The ceria located on the external surface of MFI did not have any negative effects on the catalytic performance, while the lanthana dispersed in the micropores lowered the conversion in MTO. The locations and dispersed states of ceria and lanthana were systematically discussed in the relation to their catalytic performance as blocking modifiers.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (271 K)Download as PowerPoint slide

Keywords
MFI zeolite; Ceria and lanthana impregnation; MTO reaction; Catalytic performance
First Page Preview
Ceria and lanthana as blocking modifiers for the external surface of MFI zeolite
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 476, 22 April 2014, Pages 175–185
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