title: Ab Initio Calculation of Rate Constants for Molecule-Surface Reactions with Chemical Accuracy.
abstract: The ab initio prediction of reaction rate constants for systems with hundreds of atoms with an accuracy that is comparable to experiment is a challenge for computational quantum chemistry. We present a divide-and-conquer strategy that departs from the potential energy surfaces obtained by standard density functional theory with inclusion of dispersion. The energies of the reactant and transition structures are refined by wavefunction-type calculations for the reaction site. Thermal effects and entropies are calculated from vibrational partition functions, and the anharmonic frequencies are calculated separately for each vibrational mode. This method is applied to a key reaction of an industrially relevant catalytic process, the methylation of small alkenes over zeolites. The calculated reaction rate constants (free energies), pre-exponential factors (entropies), and enthalpy barriers show that our computational strategy yields results that agree with experiment within chemical accuracy limits (less than one order of magnitude).
authors.affiliation: Institut für Chemie, Humboldt-Universität, Unter den Linden 6, 10099, Berlin, Germany.|Department of Chemistry and Applied Biosciences, ETH Zurich, c/o USI Campus, Via Giuseppe Buffi 13, 6900, Lugano, Ticino, Switzerland.
authors.forename: GiovanniMaria
authors.initials: G
authors.lastname: Piccini
authors.affiliation: Institut für Chemie, Humboldt-Universität, Unter den Linden 6, 10099, Berlin, Germany.
authors.forename: Maristella
authors.initials: M
authors.lastname: Alessio
authors.affiliation: Institut für Chemie, Humboldt-Universität, Unter den Linden 6, 10099, Berlin, Germany. js@chemie.hu-berlin.de.
authors.forename: Joachim
authors.initials: J
authors.lastname: Sauer
keywords: ab initio calculations; anharmonic vibrations; free energy calculations; transition states; zeolites