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Dibenzothiophene hydrodesulfurization over cobalt phosphide catalysts prepared through a new synthetic approach: Effect of the support

Paper ID Volume ID Publish Year Pages File Format Full-Text
47519 46474 2009 14 PDF Available
Title
Dibenzothiophene hydrodesulfurization over cobalt phosphide catalysts prepared through a new synthetic approach: Effect of the support
Abstract

Several cobalt phosphide catalysts, with a cobalt loading of 10 wt%, were prepared by means of temperature-programmed reduction (TPR) of cobalt(II) hydrogenphosphite (Co(HPO3H)2) supported on different carriers: two mesoporous supports, MCM-41 and zirconium doped MCM-41 (MCM-Zr), as well as two commercial supports, SiO2 (Cab-osil) and γ-Al2O3. The purpose of this work is to study the role of the support on the formation of CoP or Co2P and the analysis of the catalytic activity in the hydrodesulfurization (HDS) of dibenzothiophene (DBT). It is the CoP phase which is favoured on these catalysts under the given experimental conditions, except for that supported on γ-Al2O3 (CoP-10 (Al)), which only displays the diffraction lines of the Co2P phase after the reduction process. The interaction support–precursor salt seems to determine which of the phases is formed. The catalytic results showed that this family of catalysts obtained high DBT conversion values at high temperatures, mainly via the direct desulfurization (DDS) route, i.e., yielding biphenyl (BP) as majority product and attaining turnover frequency (TOF) values of 0.87 × 10−3 s−1. The stability with time on stream showed that the silica (Cab-osil) supported catalyst, CoP-10 (Cab), was highly stable with time on stream (48 h) with conversion values close to 100% and with a performance similar to that of Ni2P catalysts and better than other cobalt phosphide catalysts reported in the literature. In contrast, the CoP-10 (Zr) and CoP-10 (Si) samples decrease in activity after 16 h on stream, although their conversions are between 65% and 70% after 48 h on stream. Finally, the CoP-10 (Al) catalyst provided lower conversion values and underwent deactivation with time on stream due to the low activity of the Co2P compound formed on this sample. Furthermore, the analysis of the spent catalyst showed the presence of sulfur on the surface, assigned to the formation of phosphosulfide species.

Keywords
Mesoporous MCM-41; Silica; Alumina; MCM-Zr; Cobalt phosphide; Dibenzothiophene; HDS
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Dibenzothiophene hydrodesulfurization over cobalt phosphide catalysts prepared through a new synthetic approach: Effect of the support
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Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis B: Environmental - Volume 92, Issues 1–2, 19 October 2009, Pages 100–113
Authors
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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