Methanation and HDS catalysts based on sulfided, bimetallic clusters

Conference · Wed Jan 01 00:00:00 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-; TRN: 87-009635
• Journal Information: Prepr. Pap., Am. Chem. Soc., Div. Fuel Chem.; (United States), Vol. 31:3; Conference: ACS symposium on syngas conversion catalysis advances in gasification, Santa Clara, CA, USA, 7 Sep 1986
• Country of Publication: United States
• Language: English

Related Subjects

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