Ab initio molecular dynamics simulations investigating proton transfer in perfluorosulfonic acid functionalized carbon nanotubes.
Proton dissociation and transfer were examined with ab initio molecular dynamics (AIMD) simulations of carbon nanotubes (CNT) functionalized with perfluorosulfonic acid (-CF(2)SO(3)H) groups with 1-3 H(2)O/SO(3)H. The CNT systems were constructed both with and without fluorine atoms covalently bound to the walls to elucidate the effects of the presence of a strongly hydrophobic environment, the fluorine, on proton dissociation, hydration, and stabilization. The simulations revealed that the dissociated proton was preferentially stabilized as a hydrated hydronium cation (i.e., Eigen like) in the fluorinated CNTs but as a Zundel (H(5)O(2)(+)) cation in the nonfluorinated CNTs. This feature is attributed to the fluorine atoms forming hydrogen bonds with the water molecules coordinated to the central hydronium ion.
Habenicht
Bradley F
BF
Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996, USA.
Paddison
Stephen J
SJ
Tuckerman
Mark E
ME
D005461:Fluorine / Q000737:chemistry; D005465:Fluorocarbon Polymers / Q000737:chemistry*; D056004:Molecular Dynamics Simulation; D037742:Nanotubes, Carbon / Q000737:chemistry*; D009861:Onium Compounds / Q000737:chemistry; D011522:Protons
D005465:Fluorocarbon Polymers; D037742:Nanotubes, Carbon; D009861:Onium Compounds; D011522:Protons; D005461:Fluorine; C040402:perfluorosulfonic acid; C027727:hydronium ion