Insight from Atomistic Simulations of Protonation Dynamics at the Nanoscale

Abstract

In this paper, we give an overview of the role of molecular dynamics (MD) simulations in the field of proton exchange membranes. We focus on structural and dynamical findings regarding the topology of hydrogen bond networks and proton diffusion. On the one hand, findings about water‐containing polymer electrolyte membrane fuel cell materials, such as Nafion and liquid containing pore materials are discussed. On the other hand, proton conduction in water‐free systems is elucidated. Here, the focus lies on phosphonic acids, which possess a rigid structure, and polymers based on phosphonic acids.

Orientation of non-spherical protonated water clusters revealed by infrared absorption dichroism

“…Water is an excellent conductor for protons since the Grotthuss mechanism allows for transport of protons via the fast motion of a H 3 O + defect 1 , 2 . The potential of water to efficiently conduct protons is used in various technological applications such as fuel cells and electrochemical devices 3 – 5 . Proton transfer events are key for many essential biological functions; consequently, one finds protein-bound water molecules and internal water wires in proton-conducting transmembrane proteins such as cytochrome c oxidase, photosystem II, bacteriorhodospin, and channelrhodopsin 6 – 9 .…”

Correlated interfacial water transport and proton conductivity in perfluorosulfonic acid membranes

“…Computational work has arguably more successfully targeted the transport mechanisms and relation between water and proton transport in PFSA PEMs (reviewed in refs. 25 and 26). An important quality of these theoretical studies is the derived mechanistic insight into the proton transport mechanism for differing hydration and polymer structure.…”