Methanation and HDS catalysts based on sulfided, bimetallic clusters

Conference · Wed Jan 01 04:00:00 EST 1986 · Prepr. Pap., Am. Chem. Soc., Div. Fuel Chem.; (United States)

OSTI ID:6888265

Curtis, M D; Schwank, J; Thompson, L; Williams, P D; Baralt, O

Environmental concerns have led to an increased interest in hydrotreating catalysts, i.e. catalysts for hydrodesulfurization (HDS) or hydrodenitrogenation (HDN). Although HDS may be catalyzed by bulk or supported MoS/sub 2/ and related sulfides, the most effective catalysts are those derived from ''sulfided cobalt molybdate'' supported on Al/sub 2/O/sub 3/. These catalysts are prepared conventionally by impregnating the alumina support with solutions of molybdate ions and cobaltous ions. The impregnated support is then calcined to convert the adsorbed species to their respective oxides. The supported metal oxides are then converted to sulfides (''sulfided'') with a mixture of H/sub 2/ and H/sub 2/S (or the feed stream itself) at temperatures in the range 300-400/sup 0/C. Alternate promoters, e.g. Ni and Fe, may be used in the place of Co, but the resulting catalysts usually show a lower activity. Despite intensive study, the exact nature of the active ''CoMoS'' phase is still uncertain, and hence the role of the Co promoter and the exact mechanism of HDS remain obscure. XPS and Mossbauer Emission Spectroscopy has been used to show that a ''CoMoS'' phase, distinct from Co/sub 9/S/sub 8/ or MoS/sub 2/, is present and that the activity of the catalyst parallels the amount of this CoMoS phase present. More recently, EXAFS has been used to study these cobalt molybdate catalysts in both the oxidized and sulfided states.

• Research Organization: Departments of Chemistry and Chemical Engineering, The Univ. of Michigan, Ann Arbor, MI 48109
• OSTI ID: 6888265
• Report Number(s): CONF-8609181-
• Conference Information: Journal Name: Prepr. Pap., Am. Chem. Soc., Div. Fuel Chem.; (United States) Journal Volume: 31:3
• Country of Publication: United States
• Language: English

Related Subjects

090121* -- Hydrocarbon Fuels-- Chemical Synthesis-- (1976-1989)
10 SYNTHETIC FUELS
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201 -- Chemical & Physicochemical Properties
ALKANES
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CALCINATION
CATALYST SUPPORTS
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL PREPARATION
CHEMICAL REACTIONS
COHERENT SCATTERING
DECOMPOSITION
DESULFURIZATION
DIFFRACTION
ELECTROMAGNETIC RADIATION
ELECTRON SPECTROSCOPY
HYDROCARBONS
HYDROGEN COMPOUNDS
HYDROGEN SULFIDES
HYDROGENATION
IMPREGNATION
IONIZING RADIATIONS
METHANATION
METHANE
MOESSBAUER EFFECT
MOLYBDENUM COMPOUNDS
MOLYBDENUM SULFIDES
ORGANIC COMPOUNDS
OXIDATION
OXIDES
OXYGEN COMPOUNDS
PHOTOELECTRON SPECTROSCOPY
PYROLYSIS
RADIATIONS
REFRACTORY METAL COMPOUNDS
SCATTERING
SPECTROSCOPY
SULFIDATION
SULFIDES
SULFUR COMPOUNDS
SYNTHESIS
THERMOCHEMICAL PROCESSES
TRANSITION ELEMENT COMPOUNDS
X RADIATION
X-RAY DIFFRACTION