The preparation and catalytic applications of silica, alumina, and zirconia supported thermally resistant mono and bimetallic catalysts. Final report, December 1, 1992 - November 30, 1995

AbstractRecent results obtained in studying mono- and bimetallic catalysts for selective hydrogenation of unsaturated carbonyl compounds, even unsaturated ones, acetylenic and nitro compounds as well as CO and bio-available alcohols oxidation are reviewed from the standpoint of the strong interaction between the metal nanoparticles, on the one hand, and two metals in the composition of bimetallic nanoparticles, on the other hand. Such interactions were demonstrated to result in partial positive or negative charging of metal nanoparticles, which, in turn, changes their adsorption and catalytic properties, especially with respect to the reactions involving hydrogen. Among the systems studied, Au–Pt, Au–Pd, Au–Cu, Au–Fe, Pt–WOx, Fe–Pd, Fe–Pt, Fe–Cu nanoparticles prepared by the redox procedure are considered to be most perspective in diverse catalytic applications because of the proper combination of the particle size and the electronic state of the metals.

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Fluidized Catalytic Cracking Catalyst Microstructure as Determined by A Scanning Ion Microprobe

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100135113 ◽

1990 ◽

Vol 48 (2) ◽

pp. 302-303

Author(s):

J.K. Lampert ◽

G.S. Koermer ◽

J.M. Macaoy ◽

J.M. Chabala ◽

R. Levi-Setti

Keyword(s):

Catalytic Cracking ◽

Secondary Ion Mass Spectrometry ◽

Fuel Oil ◽

Ion Microprobe ◽

Fluidized Catalytic Cracking ◽

Ion Probe ◽

Silica Alumina ◽

Resolution Imaging ◽

The University ◽

High Spatial Resolution Imaging

We have used high spatial resolution imaging secondary ion mass spectrometry (SIMS) to differentiate mineralogical phases and to investigate chemical segregations in fluidized catalytic cracking (FCC) catalyst particles. The oil industry relies on heterogeneous catalysis using these catalysts to convert heavy hydrocarbon fractions into high quality gasoline and fuel oil components. Catalyst performance is strongly influenced by catalyst microstructure and composition, with different chemical reactions occurring at specific types of sites within the particle. The zeolitic portions of the particle, where the majority of the oil conversion occurs, can be clearly distinguished from the surrounding silica-alumina matrix in analytical SIMS images.The University of Chicago scanning ion microprobe (SIM) employed in this study has been described previously. For these analyses, the instrument was operated with a 40 keV, 10 pA Ga+ primary ion probe focused to a 30 nm FWHM spot. Elemental SIMS maps were obtained from 10×10 μm2 areas in times not exceeding 524s.

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