Competition between water and hydrogen peroxide at Ti center in Titanium zeolites. An ab initio study

A combined Car−Parrinello molecular dynamics blue moon sampling approach has been adopted to study the competitive attack of H2O and H2O2 at a tetracoordinated Titanium site in a Ti−zeolite. The results indicate that, although the attack of water to form a trigonal bipyramidal center is thermodynamically more stable, the attack of hydrogen peroxide to form a similar adduct is kinetically favored. In both cases, solvent cooperation is effective in the formation of the adducts. The relevance of such a result in relation to the catalytic properties of Ti−zeolites is discussed.