Progressing from Identifying, to Synthesizing and Designing Active Sites in Heterogeneous Catalysts

Whereas being able to construct catalytic active sites by design is an ultimate goal in heterogeneous catalysis, it remains a challenge to achieve this in general. An example is presented to show the challenge in identifying the active form of the catalyst in Au-catalyzed selective epoxidation of cyclooctene with molecular oxygen.  Another example illustrates success in constructing the active site of a supported Sn oxide catalyst in which the active form is known, yet the resulting catalyst exhibits unanticipated activity due to Brønsted acidity, in addition to the expected Lewis acidity.