Jump to main content
Jump to site search

Issue 3, 2014
Previous Article Next Article

Equilibrium properties of the reaction H2 ⇌ 2H by classical molecular dynamics simulations

Author affiliations

Abstract

We have developed a classical molecular dynamics model for the hydrogen dissociation reaction, containing two- and three-particle potentials derived by Kohen, Tully and Stillinger. Two fluid densities were investigated for a wide range of temperatures, and 11 fluid densities were considered for one temperature. We report the temperature range where the degree of reaction is significant, and also where a stable molecule dominates the population in the energy landscape. The three-particle potential, which is essential for the reaction model and seldom studied, together with the two-particle interaction lead to a large effective excluded volume diameter of the molecules in the molecular fluid. The three-particle interaction was also found to give a large positive contribution to the pressure of the reacting mixture at high density and/or low temperatures. From knowledge of the dissociation constant of the reaction and the fluid pressure, we estimated the standard enthalpy of the dissociation reaction to be 430 kJ mol−1 (ρ = 0.0695 g cm−3) and 380 kJ mol−1 (ρ = 0.0191 g cm−3). These values are in good agreement with the experimental vaule of 436 kJ mol−1 under ambient pressure. The model is consistent with a Lennard-Jones model of the molecular fluid, and may facilitate studies of the impact of chemical reactions on transport systems.

Graphical abstract: Equilibrium properties of the reaction H2 ⇌ 2H by classical molecular dynamics simulations

Back to tab navigation

Article information


Submitted
01 Oct 2013
Accepted
06 Nov 2013
First published
08 Nov 2013

Phys. Chem. Chem. Phys., 2014,16, 1227-1237
Article type
Paper

Equilibrium properties of the reaction H2 ⇌ 2H by classical molecular dynamics simulations

R. Skorpa, J. Simon, D. Bedeaux and S. Kjelstrup, Phys. Chem. Chem. Phys., 2014, 16, 1227
DOI: 10.1039/C3CP54149E

Social activity

Search articles by author

Spotlight

Advertisements