Properties of supported metal catalysts. Progress report, 1 Apr 1980-1 March 1981

Technical Report · Sun Mar 01 04:00:00 EST 1981

DOI:https://doi.org/10.2172/6534715· OSTI ID:6534715

Butt, J. B.; Cohen, J. B.

The set of Pd/SiO/sub 2/ catalysts described in Report COO-4254-3 has been further characterized by in-situ, controlled atmosphere x-ray diffraction studies. In-situ reaction studies have also been conducted for methylcyclopropane hydrogenolysis and the formation of palladium hydride has been detected for the first time during a catalytic reaction. Isotopic exchange between cyclopentane and deuterium has been investigated for the series. This reaction is structure sensitive with the turnover number increasing monotonically with percentage metal exposed. Selectivity for exchange is also structure sensitive, with the ratio of d/sub 10//d/sub 5/ steadily declining with increasing percentage exposed. Similar behavior has been found for the hydrogenation of propylene, although the patterns of structure sensitivity differ. The mean square amplitude of vibration of the Pt atoms (measured with x-rays) has been obtained in situ in different gas environments; it has been found to increase with increasing temperature of H/sub 2/ reduction during pretreatment. For low percent Pt exposed in these catalysts, it was found that Pt changes form with increasing temperature of hydrogen reduction during pretreatment. The volume fraction determined from the area of the diffraction peak decreases appreciably. An examination of the Pt fluourescent x-rays however, shows that the Pt is still present.

• Research Organization: Northwestern Univ., Evanston, IL (USA)
• Sponsoring Organization: USDOE
• DOE Contract Number: AS02-77ER04254
• OSTI ID: 6534715
• Report Number(s): DOE/ER/04254-4
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
400301 -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
400303 -- Organic Chemistry-- Isotope Exchange & Isotope Separation-- (-1987)
ALKANES
ALKENES
CATALYST SUPPORTS
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTIONS
CYCLOALKANES
DEUTERIUM
ELEMENTS
HYDRIDES
HYDROCARBONS
HYDROGEN
HYDROGEN COMPOUNDS
HYDROGEN ISOTOPES
HYDROGENATION
ISOTOPES
ISOTOPIC EXCHANGE
LIGHT NUCLEI
METALS
NONMETALS
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PALLADIUM
PALLADIUM COMPOUNDS
PALLADIUM HYDRIDES
PLATINUM METALS
PROPYLENE
RESEARCH PROGRAMS
SILICON COMPOUNDS
SILICON OXIDES
STABLE ISOTOPES
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS