The catalytic properties of zeolite-supported metal catalysts

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1988

OSTI ID:6798585

Wu, J C.S.

Y-zeolite, A-zeolite, and SAPO-5 supported-metal (Ru and Rh) catalysts were studied by XRD, NMR, AA, TEM, TPD, H{sub 2} chemisorption and catalytic reactions. The results of Ru/dealuminated Y-zeolite catalysts showed that the higher the dealumination the higher the metal dispersion. The activity and selectivity of CO hydrogenation were found to be correlated to the strength and concentration of the acidity. The metal particle size and location of a series of A zeolite-supported Ru catalysts have been investigated by ethane hydrogenolysis and cyclopropane hydrogenation as well as by H{sub 2} chemisorption and TEM. Catalysts prepared by adding a Ru precursor to the synthesis gel had metal dispersed intrazeolitically. Catalysts prepared by ion exchange of Ru with A zeolite had metal particles primarily on the surface of the zeolite crystallites. All metal sites are accessible for ethane hydrogenolysis; however, molecular sieving strongly influenced cyclopropane hydrogenation. SAPO-5 supported Rh catalyst were studied by CO hydrogenation. The activity showed an order of magnitude decrease with increasing reduction temperature while those RhHY and Rh/SiO{sub 2} were essentially insensitive to reduction temperature in the range 300-500 C. The H{sub 2} chemisorption in RhSAPO-5 was also suppressed by a factor of 2 as the reduction temperature was raised to 500 C. It is suggested that phosphorus, perhaps in the form of impurity amorphous AlPO{sub 4}, in SAPO-5 played an important role in determining the CO hydrogenation activity of Rh. H{sub 2} TPD was carried out on a series of alkali cation exchange Ru/Y catalysts. The TPD spectra indicated that the alkali cations in zeolite had no significant effect on the H{sub 2} desorption of Ru in these catalysts.

• Research Organization: Pittsburgh Univ., PA (USA)
• OSTI ID: 6798585
• Country of Publication: United States
• Language: English

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ABSORPTION SPECTROSCOPY
ADSORBENTS
ALKANES
ALUMINIUM
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CATALYST SUPPORTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL PREPARATION
CHEMICAL PROPERTIES
CHEMICAL REACTIONS
CHEMISORPTION
COHERENT SCATTERING
CONTROL
CYCLOALKANES
DEHYDROGENATION
DEMETALLIZATION
DESORPTION
DIFFRACTION
ELECTRON MICROSCOPY
ELEMENTS
ETHANE
HYDROCARBONS
HYDROGEN
HYDROGENATION
INORGANIC ION EXCHANGERS
ION EXCHANGE MATERIALS
MAGNETIC RESONANCE
MATERIALS
METALS
METHANATION
MICROSCOPY
MINERALS
MOLECULAR SIEVES
NONMETALS
NUCLEAR MAGNETIC RESONANCE
ORGANIC COMPOUNDS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PARTICLE SIZE
PHOSPHORUS
PLATINUM METALS
PROMOTERS
PROPANE
RESONANCE
RHODIUM
RUTHENIUM
SCATTERING
SEPARATION PROCESSES
SILICA
SILICON COMPOUNDS
SILICON OXIDES
SIZE
SORPTION
SPECTROSCOPY
SURFACE PROPERTIES
SYNTHESIS
TEMPERATURE CONTROL
TRANSITION ELEMENTS
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION
ZEOLITES