Structure and catalytic activity of Ru(Rh)/ThO sub 2 CO hydrogenation and NiW/Al sub 2 O sub 3 hydrodesulfurization catalysts
The surface structures of catalysts prepared from oxidation of Ru{sub x}Th{sub y} intermetallics and Ru/ThO{sub 2} supported catalysts prepared by impregnation were studied using X-ray Photoelectron Spectroscopy (ESCA or XPS), ion scattering spectroscopy (ISS), X-ray diffraction (XRD), gravimetric analysis and chemisorption. XRD measurements and gravimetric analysis indicate that all Ru{sub x}Th{sub y} intermetallics are extensively decomposed on oxidation at 350{degree}C. ESCA and ISS studies showed surface enrichment in Th for all intermetallic-derived catalysts. The structure of the intermetallic-derived catalysts can best be described as Ru particles embedded in a ThO{sub 2}-rich overlayer. In contrast, ESCA and ISS measurements indicate that the surface structure of the impregnated catalyst consists of Ru particles deposited on top of the ThO{sub 2} carrier. The methane selectivity for the catalysts derived from oxidation of Ru{sub 3}Th{sub 7} is significantly higher than that for the corresponding supported Ru/ThO{sub 2} catalyst. The TOF for CO hydrogenation of the catalyst derived from oxidation of Ru{sub 3}Th{sub 7} is two orders of magnitude higher than that of the corresponding Ru/ThO{sub 2} catalyst. The CO hydrogenation TOF of Rh/ThO{sub 2} catalysts prepared from Rh(NO{sub 3}){sub 3}, was not affected by Rh dispersion, impregnation medium and activation procedure. A modified ESCA method, was used to determine the extent of Ni reduction and sulfidation in a series of Ni/Al{sub 2}O{sub 3} catalysts. The extent of Ni reduction and sulfidation measured by the modified ESCA method correlated well with the data obtained by gravimetric analysis and chemical extraction.
- Research Organization:
- Pittsburgh Univ., PA (USA)
- OSTI ID:
- 6067425
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
Similar Records
Characterization of catalysts derived from oxidation of Ru sub x Th sub y intermetallics
Spectroscopic characterization of hydrotreating catalysts containing cobalt, nickel, and molybdenum
Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
01 COAL, LIGNITE, AND PEAT
02 PETROLEUM
CARBON MONOXIDE
HYDROGENATION
METHANATION
CATALYSTS
SURFACE PROPERTIES
NICKEL
CATALYTIC EFFECTS
RHODIUM
RUTHENIUM
TUNGSTEN
ALUMINIUM OXIDES
CATALYSIS
CATALYST SUPPORTS
CHEMICAL ACTIVATION
CHEMICAL PREPARATION
CHEMICAL REACTION KINETICS
CHEMISORPTION
COMPARATIVE EVALUATIONS
DESULFURIZATION
GRAVIMETRIC ANALYSIS
IMPREGNATION
INTERMETALLIC COMPOUNDS
ION SCATTERING ANALYSIS
METHANE
MICROSTRUCTURE
NITRATES
OXIDATION
PHOTOELECTRON SPECTROSCOPY
REDUCTION
RHODIUM COMPOUNDS
SULFIDATION
SYNTHESIS
THORIUM OXIDES
TUNGSTEN SULFIDES
X-RAY DIFFRACTION
X-RAY SPECTROSCOPY
ACTINIDE COMPOUNDS
ALKANES
ALLOYS
ALUMINIUM COMPOUNDS
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
CHEMICAL ANALYSIS
CHEMICAL REACTIONS
COHERENT SCATTERING
CRYSTAL STRUCTURE
DIFFRACTION
ELECTRON SPECTROSCOPY
ELEMENTS
HYDROCARBONS
KINETICS
METALS
NITROGEN COMPOUNDS
NONDESTRUCTIVE ANALYSIS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PLATINUM METALS
QUANTITATIVE CHEMICAL ANALYSIS
REACTION KINETICS
REFRACTORY METAL COMPOUNDS
SCATTERING
SEPARATION PROCESSES
SORPTION
SPECTROSCOPY
SULFIDES
SULFUR COMPOUNDS
THORIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
TUNGSTEN COMPOUNDS
400201* - Chemical & Physicochemical Properties
010408 - Coal
Lignite
& Peat- C1 Processes- (1987-)
010402 - Coal
Lignite
& Peat- Purification & Upgrading
020400 - Petroleum- Processing