Quantum-Chemical Modeling of the Dissociative Adsorption of Molecular Hydrogen onto the Tin Dioxide Surface

The hydrogen adsorption, dissociation, and migration on the tin dioxide surface have been modeled by the density functional theory method within the generalized gradient approximation (GGA) under periodic conditions using a projector-augmented plane-wave (PAW) basis set with a pseudopotential. It has been demonstrated that dissociative chemisorption onto the tin dioxide surface depends on the adsorption site and the surface structure and that there are places on the surface where dissociation can occur with a low barrier of 0.1-0.2 eV to yield a primary isomer in which one of the hydrogen atoms is bound to the tin atom and the other, to an oxygen atom; the second dissociation even at the same place is possible only if the primary isomer overcomes a barrier of similar to 1 eV and transforms to the secondary isomer with two O-H bonds.