NH3 as simple clathrate-hydrate catalyst: Experiment and theory

Kilic M., Devlin J. P. , Uras-Aytemiz N.

JOURNAL OF CHEMICAL PHYSICS, cilt.148, 2018 (SCI İndekslerine Giren Dergi) identifier identifier identifier

  • Cilt numarası: 148 Konu: 23
  • Basım Tarihi: 2018
  • Doi Numarası: 10.1063/1.5029908


The catalytic action of NH3 within the all-vapor approach for instant clathrate hydrate (CH) formation is studied using both FTIR spectroscopy and ab initio molecular dynamics simulations. A unique property of NH3, namely, the rapid abundant penetration and occupation of the water network, creates defects, particularly Bjerrum D-defects, in the hydrate frame that are generally stabilized by guest NH3 molecules in the cages. Furthermore, insertion of NH3 seriously disturbs the hydrate network where the guest NH3 molecules also make fluxional H-bonds with the host water molecules. These defects strongly facilitate a sub-second formation of the simple NH3 s-II gas hydrate at 160 K. FTIR spectra of aerosols of the NH3 s-II CH have been measured, and the displacement of both small and large cage NH3 guests by CO2 and tetrahydrofuran is examined. Published by AIP Publishing.