Computational Study of One Layer of Protonated Mordenite (H-MOR) as Ammonia and Water Molecule Adsorbent using Car-Parrinello Molecular Dynamics

Abstract

One layer of protonated mordenite (H-MOR) was observed by find the changes of adsorbed energies through by ammonia (NH3) and water (H2O) molecule. The energy changes are calculating when adsorbed molecules added at the system, it lies on 7.5 A from outer atoms moved to reach the core of the system through 12 membered rings (move on z axis) near T4 Bronsted site, then we also consider the opposite case. The base structure of H-MOR optimized by Direct Inversion in the Iterative Subspace (ODIIS) with DFT in CPMD program package. The result shows the energy of the system decrease when NH3 lies inside the cavity of mordenite for both systems. The shape is like well, when the adsorbed energies for NH3 system is similar with H2O system at the surface (i.e. 90 kJ/mol) but lower inside the cavity (i.e. 140 kJ/mol for NH3 and 120 kJ/mol for H2O).