Heterogeneous catalysis is one of the oldest nanosciences. Although
model catalysts can be designed, synthesized, and, to a certain degree,
characterized, industrial heterogeneous catalysts are often chemically
and physically complex systems that have been developed through many
years of catalytic art, technology, and science. The preparation of
commercial catalysts is generally not well controlled and is often
based on accumulated experiences. Catalyst characterization is thus
critical to developing new catalysts with better activity, selectivity,
and/or stability. Advanced electron microscopy, among many
characterization techniques, can provide useful information for the
fundamental understanding of heterogeneous catalysis and for guiding
the development of industrial catalysts. In this article, we discuss
the recent developments in applying advanced electron microscopy
techniques to characterizing model and industrial heterogeneous
catalysts. The importance of understanding the catalyst nanostructure
and the challenges and opportunities of advanced electron microscopy in
developing nanostructured catalysts are also discussed.