CaSTL Seminar with Horia Metiu

Oxides catalyze some very interesting alkane reactions but tend to do it poorly. In this talk I describe 
computational work whose goal is to propose various chemical modifications of oxide surfaces aimed 
at making them better catalysts.  I will focus particularly on cation doping.  I will present calculations 
that show that lower-valence dopants improve the oxidizing power of a host oxide by activating surface 
oxygen atoms, while higher-valence dopants improve the oxidizing power by activating chemisorbed oxygen.  
The calculations performed so far suggest a general rule: a Lewis acid on the surface facilitates strongly 
the binding of a Lewis base, and vice versa.  This rule explains a large number of computational results, 
has predictive power, and seems to be supported by experiments.  We explore the activation of alkanes 
by doped oxides by calculating the activation energy for breaking the C-H bond.  We find an interesting 
and general mechanism through which oxides perform this reaction.