These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Hydrogen evolution from formic acid in an ionic liquid solvent: a mechanistic study by ab initio molecular dynamics.
    Author: Bhargava BL, Yasaka Y, Klein ML.
    Journal: J Phys Chem B; 2011 Dec 08; 115(48):14136-40. PubMed ID: 21774513.
    Abstract:
    The reversible decomposition of formic acid (HCOOH ⇌ CO(2) + H(2)) has been attracting attention for its potential utility in hydrogen storage and production. It is therefore of interest to explore the influence of solvents on the decomposition reaction. To this end, Born-Oppenheimer (BO) molecular dynamics (MD) calculations have been performed to explore the mechanism involved in hydrogen (H(2)) evolution from formic acid decomposition in an ionic liquid solvent. Specifically, for a solvent consisting of 1,3-dimethylimidazolium cations and formate anions, evolution of hydrogen (H(2)) and carbon dioxide (CO(2)) was observed within a few picoseconds when BO-MD trajectories were carried out at an elevated temperature of 3000 K. The observed dehydrogenation involved a reaction between a formic acid solute and a nearby solvent formate anion. The observed mechanism contrasts with the unimolecular mechanism proposed in the gas phase. Specifically, in the ionic liquid, the reaction is initiated from a C-H bond dissociation of a formate anion to produce a short-lived hydride anion, which subsequently captures the acidic proton of a nearby formic acid molecule. The present BO-MD computations suggest that the high reducing ability of formic acid in the ionic liquid is due in part to its acid-dissociated form: the formate anion, which is encouraged to dissociate into a hydride anion and CO(2) by the strong electrostatic field of the ionic liquid solvent.
    [Abstract] [Full Text] [Related] [New Search]