The ability to understand and control the microstructure of materials under “real life” conditions is of great interest to both the scientific and industrial communities. In recent years, a variety of “ex-situ” TEM methods have been developed to improve this knowledge base.

ExxonMobil's dedicated reactor system developed for “ex-situ” TEM was used to study the oxidation and reduction of copper on a carbon film and Cu on a Si support. By following the oxidation of specific Cu particles, it was possible to illustrate the oxidation process. A standard, commercially available, 200 mesh Cu grid covered with a holey C support film was used for the Cu on C study. Small Cu islands were vapor deposited from the grid onto the C film during a high temperature reduction in the reactor (Figure 1). The grid was transferred under inert conditions into the TEM where the Cu metal islands were imaged (Figure 2a).