fulltext.study @t Gmail

Influence of the acidity of nanostructured CoMo/P/Ti-HMS catalysts on the HDS of 4,6-DMDBT reaction pathways

Paper ID Volume ID Publish Year Pages File Format Full-Text
48346 46503 2008 14 PDF Available
Title
Influence of the acidity of nanostructured CoMo/P/Ti-HMS catalysts on the HDS of 4,6-DMDBT reaction pathways
Abstract

The influence of catalyst acidity on the reaction mechanism of the 4,6-dimethyldibenzothiophene (4,6-DMDBT) hydrodesulfurization (HDS) over CoMo hydrotreating catalysts was studied using a batch autoclave and fixed-bed reactor (T = 598 K and P = 5.5 MPa). P-free Ti-HMS and P-containing P/Ti-HMS mesoporous siliceous materials were synthesized and used as supports. The effect of the catalyst preparation method (successive vs. simultaneous impregnation) and phosphorous addition on catalyst acidity was studied by TPD-NH3 and DRIFT-NH3 techniques. For all synthesized catalysts, the reaction proceeds via dealkylation (DA) and isomerization (ISO) pathways, with the later being the main reaction route. Incorporation of Co and Mo phases by simultaneous impregnation was found to be the best method for catalyst preparation, whereas P-addition promote the isomerization route of 4,6-DMDBT transformation to a greater extent than the dealkylation route. On the contrary, the reaction on a CoMoP/γ-Al2O3 reference catalyst proceeds via HYD and DDS reaction pathways, the later being the main reaction route. The catalyst acidity–activity correlation indicates that both activity and selectivity depend largely on the presence of Brønsted acid sites as well as on the total amount of Brønsted and Lewis acid sites. By correlating HRTEM-activity data, the enhancement of activity and isomerization observed with the catalyst prepared by simultaneous impregnation and modified with P was related to the cumulative effects of the lower size of MoS2 slabs and their higher surface density.

Keywords
HDS; DBT; 4,6-DMDBT; CoMo catalysts; Mesoporous silica; Phosphorous; Brønsted acidity
First Page Preview
Influence of the acidity of nanostructured CoMo/P/Ti-HMS catalysts on the HDS of 4,6-DMDBT reaction pathways
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 B: Environmental - Volume 80, Issues 1–2, 15 April 2008, Pages 1–14
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