The Structure of Catalysts Studied Using Environmental Transmission Electron Microscopy

In the chemical industry, approximately 85–90 % of all chemicals are made via catalytic processes (Chorkendorff and Niemantsverdriet 2003). Catalysts are used in processes ranging from synthesis of fine chemicals over fuel refinement to abatement of pollution. Heterogeneous catalysts often comprise metal nanoparticles supported on a substrate providing a high dispersion and stabilization of the particles.

The nanoparticle surfaces hold the active sites responsible for the conversion of reactants to products. The atomic arrangement at the specific surfaces has large influence on the reaction rate, making it of high importance to be able to study such on a local scale. Something, which has become a reality with the advent of aberration corrected transmission electron microscopy (TEM) (Hansen and Wagner 2012; Yoshida et al. 2012).

Whereas this information could be obtained from more conventional high vacuum microscopy (Honkala et al. 2005; Carlsson et al. 2006; Janssens et al. 2006), the atomic arrangement, and distribution of specific surfaces are most likely different when the catalyst is in a reactive environment.