Electrosorption of Br and Cl on Ag(100): Experiments and Computer Simulations

TL;DR

This study combines experiments and simulations to analyze the electrosorption behavior of Br and Cl on Ag(100) surfaces, revealing the importance of coverage-dependent interactions for Cl.

Contribution

It introduces and compares two methods for calculating long-range adsorbate interactions and fits isotherms to experimental data, highlighting different behaviors for Br and Cl.

Findings

Constant &gamma fits Br/Ag(100) well

Coverage-dependent &gamma needed for Cl/Ag(100)

Two methods for interaction calculation compared

Abstract

We present chronocoulometry experiments and equilibrium Monte Carlo simulations for the electrosorption of Br and Cl on Ag(100) single-crystal electrode surfaces. Two different methods are used to calculate the long-range part of the adsorbate-adsorbate interactions. The first method is a truncated-sum approach, while the second is a mean-field-enhanced truncated-sum approach. To compare the two methods, the resulting isotherms are fit to experimental adsorption isotherms, assuming both a constant electrosorption valency &gamma and also a coverage-dependent &gamma. While a constant &gamma fits the Br/Ag(100) well, a coverage-dependent or potential-dependent &gamma is needed for Cl/Ag(100).