Cation redistribution upon water adsorption in titanosilicate ETS-10

Nonframework Na + cations in titanosilicate ETS-10 have been analyzed from atomistic simulation. Based on the binding energies, five types of Na + cations are classified. Type V cations located in the main channels are substantially mobile compared with type I-IV cations. Redistribution of Na + ions is observed upon H2O adsorption, in which the number of type-V ions increases while other types slightly decreases. The simulated adsorption isotherm of H2O is in good agreement with experimental data, and three adsorption sites are observed for H2O. As loading increases, the diffusion of H2O initially rises and then drops as largely determined by H2O in the main channels.