Abstract:

A key problem literally since the discovery of catalysis itself is the question of “what’s the actual, true catalyst?”. More specifically, distinguishing homogeneous catalysis from nanoparticle heterogeneous catalysis has proven to be both a critical, as well as challenging, issue in a range of organic reactions over the ≥25 years. Post setting up the history and importance of the “What’s the catalyst?” problem, the talk will present a guiding hypothesis of how to avoid being fooled by what you think is the catalyst, vs what really is the kinetically dominant catalyst, in any catalytic reaction under consideration. An instructive case history will be presented of where heterogeneous nanoparticle catalysis was uncovered when homogeneous catalysis was previously believed to be occurring. A second case history of the analogous, important problem of what is the true catalyst in photoelectrochemical homogeneous vs heterogeneous water-oxidation catalysis, en route to our sustainable energy future, will also be presented.  A Summary will be provided containing several take-home messages of interest to anyone dealing with the “What is the true catalyst?” problem in general, or with the “Is it homogeneous or heterogeneous catalysis?” question specifically.