Active Sites in Heterogeneous Photocatalysis: Brief Notes on the Identification of Their Analogies with the Standard Heterogeneous Catalysis Concept

The reaction rate concepts in heterogeneous catalysis are based on well-defined and usually well-quantified active sites. Such an active site is stable over time and its main features are typically constant. In heterogeneous photocatalysis, the active site is of different nature. Its existence depends on the instantaneous availability of photons and the variable ability of the photocatalyst to use them. In fact, a realistic expression of the active site that at least in the main feature - stability over time - resembles the classical heterogeneous catalytic concept is missing. Here, the concept of a dynamic active site of the heterogeneous oxidation photocatalyst that is (in a dynamic sense) time stable is elaborated and carefully discussed. The novelty of this approach should be seen in the straightforward applicability of standard kinetic models.

Automated summary

The concept of active sites in heterogeneous catalysis and photocatalysis differs, with the former being stable and constant, while the latter depends on the availability of photons and the catalyst's varying ability to utilize them. A dynamic active site concept for heterogeneous oxidation photocatalysts has been elaborated, allowing for straightforward application of standard kinetic models.