Monte Carlo Potential Energy Sampling for Molecular Entropy in Zeolites
Journal article, 2018

Zeolites are widely applied as molecular sieves and porous host materials for active sites in heterogeneous catalysis. Adsorption and reaction kinetics depend critically on the molecular entropy in the zeolite. In this work, we introduce a method to calculate the entropy of molecules in zeolites using Monte Carlo integration of the semiclassical partition function. The method is demonstrated for N-2 and CH4 in chabazite and MFI silicalites. We find that the molecular entropy is lowered by a factor between 1/3 and 1/2 with respect to the gas-phase value. The results are corroborated by explicit molecular dynamics simulations revealing the active molecular degrees of freedom. The possibility of accurate entropy estimations opens up for an improved description of catalytic reactions and sorption phenomena in zeolites.

Author

Mikkel Jørgensen

Competence Centre for Catalysis (KCK)

Chalmers, Physics, Chemical Physics

Lin Chen

Chalmers, Physics, Chemical Physics

Competence Centre for Catalysis (KCK)

Henrik Grönbeck

Competence Centre for Catalysis (KCK)

Chalmers, Physics, Chemical Physics

Journal of Physical Chemistry C

1932-7447 (ISSN) 1932-7455 (eISSN)

Vol. 122 35 20351-20357

Catalytic activity from first principles

Swedish Research Council (VR), 2017-01-01 -- 2020-12-31.

Areas of Advance

Nanoscience and Nanotechnology (2010-2017)

Materials Science

Subject Categories

Physical Chemistry

Theoretical Chemistry

Condensed Matter Physics

Infrastructure

C3SE (Chalmers Centre for Computational Science and Engineering)

DOI

10.1021/acs.jpcc.8b05382

More information

Latest update

2/19/2019