fulltext.study @t Gmail

Effect of Ti incorporated MWW supports on Au loading and catalytic performance for direct propylene epoxidation

Paper ID Volume ID Publish Year Pages File Format Full-Text
53302 46962 2016 11 PDF Available
Title
Effect of Ti incorporated MWW supports on Au loading and catalytic performance for direct propylene epoxidation
Abstract

•The Au nano-particles size in Ti-YNU-1 with tetrahedral Ti is smaller than that in Si/Ti-MCM-36 with tetrahedral and octahedral Ti.•The optimal reaction temperature of former is higher than later for direct propylene epoxidation.•The Si/Ti-MCM-36 mesopores seem to moderate catalyst deactivation.

Two types of novel catalysts consisting of gold nanoparticles (NPs) supported on the Ti-incorporated MWW structures were compared. One is Ti-YNU-1 with 0.67 nm micropores between expanded 2D-MWW structures, and the other is the titanosilicate pillared MCM-36 (Si/Ti-MCM-36) with 2 nm mesopores. The influences of pore structure and Ti coordination environment on the particle size of anchored Au NPs and their catalytic performances in propylene epoxidation with mixtures of H2 and O2 were investigated. The catalyst materials were characterized with Electron Probe Micro Analysis, X-ray diffraction, nitrogen sorption, UV–visible diffuse reflectance spectroscopy, transmission electron microscopy, and X-ray absorption spectroscopy. The coordination environment of Ti(IV) in Ti-YNU-1 is mainly isolated tetrahedral (Td), while that in Si/Ti-MCM-36 was found to be a mixture of Td and octahedral (Oh). The Au loading was proportional to the amount of Ti incorporated in the porous silica. The particle size of Au NPs in the Si/Ti-MCM-36 support was a little larger than that in the Ti-YNU-1 support, and it is attributed to that the highly isolated Td Ti(IV) in Ti-YNU-1 is favorable for attaining the smaller gold NPs, while the higher loading of Ti in Si/Ti-MCM-36 anchored more Au and resulted in the formation of larger Au particles. On the other hand, the mesopores in Si/Ti-MCM-36 facilitated the diffusion of the produced PO in pore structure, inhibited the further reaction for side product formation, and moderated the deactivation of catalysts.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (203 K)Download as PowerPoint slide

Keywords
MWW; Porosity; Ti coordination; Propylene epoxidation
First Page Preview
Effect of Ti incorporated MWW supports on Au loading and catalytic performance for direct propylene epoxidation
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: Catalysis Today - Volume 264, 15 April 2016, Pages 98–108
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