13. Nanocharacterization of Heterogeneous Catalysts by Ex Situ and In Situ STEM

Heterogeneous catalysts are an important set of materials that increase the rate of chemical reactions. The increase in the reaction rate can be many orders of magnitude and depends on the degree to which the activation energy of the reaction can be lowered. Heterogeneous catalysts have traditionally played major roles in fields such as fuel processing, chemical synthesis and polymer production (van Santen et al. 1999). More recently they have played increasing roles in the environmental technology, energy production and materials synthesis. The field is undergoing a significant expansion and it is widely recognized that, for substantial progress, it is necessary to develop an atomic-level understanding of the interaction between the catalyst and the reactants/product in order to design novel catalytic materials that can address the problems of the 21 st century.