Surface Structure and Morphology:
Goals are to determine surface crystal structures of various catalytic
oxides using HREM, diffraction, and XPS combined with theoretical Direct
Methods. We hope to elucidate the effect of surface structure and morphology
on reactivity using simplified model systems in the hope of extending
these results to real industrial catalytic systems.
Interested Surface: SrTiO3
  
From left: Bright field image of SrTiO3 (001)
surface after annealing in oxygen atmosphere. Inset shows diffraction
pattern demonstrating (2x1) surface structure. Direct Methods image map
of the (2x1) surface showing edge sharing octahedra. Finally, the solution
to the (2x1) surface structure demonstrating a TiO2-like
stoichiometry on the surface.
Interested Surface: alfa-Fe2O3
Prepare well ordered reproducible surfaces of alfa-Fe2O3
(hematite)
Understand the surface structure of alfa-Fe2O3
and how it varies with oxygen partial pressure and annealing temperature
Characterize the effect of reactant adsorption (CH3)
on surface structure and morphology
  
From L to R: Bright field image of ion milled alfa-Fe2O3;
diffraction pattern (inset) shows evidence for surface coverage of Fe3O4.
Bright field image after annealing in O2; diffraction
pattern (inset) shows (1x1) surface reconstruction. Schematic view of
hematite crystal structure corundum).
Interested Surface:Rutile TiO2
Characterize surface structure of TiO2 Characterize
nature of Au nanoparticles on TiO2 support
Determine how structure and morphology change during treatment
Relate this information to real supported catalytic systems
 
From L: Octahedral structure of TiO2 (rutile).
Bright field image shows faceting; diffraction pattern (inset) of c(2x2)
surface reconstruction.
Direct methods image map.
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Environmental Catalysis
