Scanning tunneling microscopic and auger electron spectroscopic of a model catalyst. Rhodium on TiO[sub 2](001)

Journal Article · Thu Jun 03 00:00:00 EDT 1993 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100124a031· OSTI ID:6053015

Poirier, G E; Hance, B K; White, J M ^[1]

---

1. Univ. of Texas, Austin (United States)

Rhodium films were vapor deposited on TiO[sub 2](001) rutile and examined in situ at various coverages and following various annealing procedures by using scanning tunneling microscopy (STM) and Auger electron spectroscopy (AES). Rh deposition at ambient temperature leads to STM images that indicate nucleation and growth of three-dimensional particles. The particles have a narrow size distribution centered around 30 A with an aspect ratio of 0.3 and are not arranged with long-range order. AES results corroborate the film thickness measured by STM. Annealing in vacuum decreases both the Rh/Ti Auger intensity ratio and the number density of particles, indicating particle coalescence at the onset of surface diffusion. Simultaneously, the apparent included volume of the particle film increases, an effect that is consistent with Rh particle encapsulation but may also be due to tip convolution. The utility of STM in morphologic characterization of oxide-supported metal particles, such as those found in catalysts and gas sensors, is demonstrated. 53 refs., 8 figs.

• OSTI ID: 6053015
• Journal Information: Journal of Physical Chemistry; (United States), Vol. 97:22; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
RHODIUM
ANNEALING
AUGER ELECTRON SPECTROSCOPY
ELECTRON MICROSCOPY
CATALYSTS
DIFFUSION
FILMS
RUTILE
TITANIUM OXIDES
CHALCOGENIDES
ELECTRON SPECTROSCOPY
ELEMENTS
HEAT TREATMENTS
MATERIALS
METALS
MICROSCOPY
MINERALS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PLATINUM METALS
RADIOACTIVE MATERIALS
RADIOACTIVE MINERALS
SPECTROSCOPY
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
360101* - Metals & Alloys- Preparation & Fabrication
360102 - Metals & Alloys- Structure & Phase Studies