A method to calculate redox potentials relative to the normal hydrogen electrode in nonaqueous solution by using density functional theory-based molecular dynamics.

Abstract

We demonstrate the redox potential calculation relative to the normal hydrogen electrode (NHE) in nonaqueous solution using a density functional theory-based molecular dynamics (DFT-MD) simulation. The calculation of the NHE in nonaqueous solution consists of two processes: the first step is the equilibrated simulation for a proton in nonaqueous solution to determine the space for inserting a proton in solution, and the second step is the thermodynamic integration method to calculate the solvation energy of the proton in the nonaqueous solution. In this work, we apply the method for a cation and an anion, i.e., copper(ii)/copper(i) and iodine/iodide in acetonitrile solution, and show that the errors in the calculated redox potential from experiments are within 0.21 V.