Ab Initio Molecular Dynamics Study of Methanol-Water Mixtures under External Electric Fields
Articolo
Data di Pubblicazione:
2020
Abstract:
Intense electric fields applied on H-bonded systems are able to induce molecular dissociations, proton transfers, and complex chemical reactions. Nevertheless, the effects induced in heterogeneous molecular systems such as methanol-water mixtures are still elusive. Here we report on a series of state-of-the-art ab initio molecular dynamics simulations of liquid methanol-water mixtures at different molar ratios exposed to static electric fields. If, on the one hand, the presence of water increases the proton conductivity of methanol-water mixtures, on the other, it hinders the typical enhancement of the chemical reactivity induced by electric fields. In particular, a sudden increase of the protonic conductivity is recorded when the amount of water exceeds that of methanol in the mixtures, suggesting that important structural changes of the H-bond network occur. By contrast, the field-induced multifaceted chemistry leading to the synthesis of e.g., hydrogen, dimethyl ether, formaldehyde, and methane observed in neat methanol, in 75:25, and equimolar methanol-water mixtures, completely disappears in samples containing an excess of water and in pure water. The presence of water strongly inhibits the chemical reactivity of methanol.
Tipologia CRIS:
03A-Articolo su Rivista
Keywords:
molecular dynamics; electric fields; methanol; aqueous solutions; proton transfer; chemical reactivity
Elenco autori:
Giuseppe Cassone, Adriano Sofia, Jiri Sponer, Marco Saitta, Franz Saija
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