1. Mark E. Tuckerman, Department of Chemistry, New York University
Connecting microscopic solvation patterns to proton transport kinetics in hydrogen-bonded media via population correlation functions
Mark E. Tuckerman, Department of Chemistry, New York University
New York, NY 10003
The transport of protons through aqueous and other hydrogen-bonded media is central to a myriad of processes, including the operation of emerging fuel-cell technologies. despite its importance, a theory connecting microscopic solvation patterns of charge defects such as hydronium (H3O+) and hydroxide (OH-), which occur in aqueous solutions, to transport kinetics is lacking. We have introduced such a theory (which recently appeared in Physical Review Letters) using the concept of population correlation functions.
By introducing “indicator functions” h(t) and H(t), where h(t)=1 if the center of the charge defect (shown in blue in the figures above) is at a particular site in the hydrogen-bond network at time t, otherwise h(t)=0, and H(t)=1 if the center remains at a particular site from t=0 up to t, the various correlation functions <h(0)h(t)>, <h(0)H(t)>,… that can be constructed lead to a rate theory capable of generating a full set of time scales that characterize the proton transport process. In this way, microscopic transport mechanisms can be validated by direct comparison to experiment. We expect theory to be applicable to a wide variety of proton transport problems.