Characterization of Active Sites in Sulfided Molybdenum/ Alumina Hydrodesulfurization Catalysts

Catalytic Active Sites in Molybdenum Based Catalysts

In situ metal, acid and metal-acid (bifunctional) catalytic active functions were prepared following partial reduction by hydrogen of MoO3 deposited on TiO2 at temperatures between 623 K and 673 K. The bifunctional structure is obtained following the reduction of MoO3 to MoO2. The metallic properties of MoO2 are attributed to the delocalized  electrons above the Mo atoms place along the C-axis...

Characterization and Hydrodesulfurization Activity of CoMo Catalysts Supported on Boron-Doped Sol-Gel Alumina

Pyridine Adsorption on Molybdenum Oxide-Alumina Catalysts

The adsorption of pyridine on a complete monolayer molybdenum oxide-Al203 catalyst was studied. Both Lewis and Bronsted acid sites are present on a catalyst with a Mo valence of -4.1. The orientation of adsorbed pyridine was studied by means of its interaction with surface OD groups, which leads to the formation of only 2-deuteriopyridine. The fraction of molybdenum ions active for hydrogenatio...

Solid State Synthesis and Characterization of Model Hydrodesulfurization Catalysts

Solid-state reactions of elemental sulfur with metallic cobalt and molybdenum powders were used to synthesize model catalysts for hydrodesulfurization (HDS). The resulting materials had a general stoichiometry of CozlMo,-,S2 with x between 0.025 and 0.3. The solid phases formed during synthesis and after exposure to typical HDS reaction conditions were identified by X-ray diffraction and select...

Characterization of active sites on Rh/SiO(2) model catalysts.

Rh/SiO(2) model catalyst surfaces are prepared under ultra-high vacuum conditions and examined in situ using scanning tunneling microscope and CO infrared reflection absorption techniques, to quantify the number and kinds of active Rh surface sites available for kinetic reaction (CO oxidation) as a function of Rh particle size. The results are compared against CO desorption measurements and ele...