Sulfidation State and Sulfur Behavior on Mo-based HDS Catalysts Supported on TiO₂ Using ³⁵S Tracer Methods

Abstract

A35 S radioisotope pulse tracer method using 35 S-labeled H2S was used to investigate the sulfidation state of Mo-based catalysts supported on TiO2. Despite the coverage of Mo species on the TiO2 support, sulfidation of the TiO2 support still occurred at 300℃. The sulfided catalysts could be reduced under H2 atmosphere. A 35 S radioisotope tracer method using 35 S-labeled dibenzothiophene ([ 35 S]DBT) was used to determine the sulfur mobility on the working sulfided Mo/TiO2 catalysts. The amount of labile sulfur (So), which represents the amount of active sites, and the release rate constant of H2S, which represents the mobility of the active site (kRE), were estimated. Compared with Mo/Al2O3 catalyst, Mo/TiO2 catalyst had slightly higher So and about 2 times higher kRE, which indicate that new mobile active sites were formed on sulfided Mo/TiO2 catalyst. Comparison of the kRE and So of titania-based and alumina-based catalysts suggested that the active phase consisted of a 'TiMoS' phase exhibiting a promoting effect similar to the well-known 'CoMoS' phase (promotion of the MoS2 active phase by Ti atoms). Hydrodesulfurization (HDS) of DBT was evaluated over Mo catalysts supported on titania synthesized by the pH swing method, which provides a TiO2 carrier with a high specific surface area (134 m

Ionic liquids assisted desulfurization and denitrogenation of fuels

“…HDS is more efficient than other methods in removal of aliphatic sulfur compounds, at the same time the removal of aromatic sulfur compounds by this method is not effective. Also HDS is not economically effective, because it requires a large amount of expensive catalyst (basically Mobased catalysts [41,42] ), as well as rather harsh process conditions, i.e. high pressure (1590 bar) and temperature (300350 o C) and additional removal of byproduct H2S with Clause processto obtain elemental sulfur.…”

On the morphology of MoS2slabs on MoS2/Al2O3catalysts: the influence of Mo loading

“…7 As an important parameter in supported MoS 2 catalysts, the effect of Mo loading on the catalyst structure and activity was intensively investigated. [8][9][10][11][12][13][14][15][16][17] While several studies suggest that the MoS 2 -Al 2 O 3 interactions may differ with Mo loading, 13,18,19 the correlation of Mo loading and MoS 2 morphology is never considered. Therefore, in this work the effect of Mo loading on the morphology of MoS 2 phase on MoS 2 /Al 2 O 3 catalysts is investigated.…”

Preparation of Alumina-supported Cobalt–molybdenum Catalysts by Sol-gel Method and Hydrodesulfurization Activities

“…Similar regulations will soon be introduced in many other maritime areas, so hydrodesulfurization of gas oil, diesel oil and fuel oil for ships will become more and more important. Therefore, further development of hydrodesulfurization catalysts has continued, especially to identify more active and selective catalyst components 1), 2) . Conventional HDS catalysts consist of MoS2 planes containing Ni or Co atoms ('NiMoS' or 'CoMoS' phase) supported on a carrier, usually γ-alumina.…”