Acetate and phosphate anion adsorption linear sweep voltammograms simulated using density functional theory |
| |
Authors: | Iman Shahidi Pour Savizi Michael J. Janik |
| |
Affiliation: | The Pennsylvania State University, Department of Chemical Engineering, 104 Fenske Laboratory, University Park, PA 16803, United States |
| |
Abstract: | Specific adsorption of anions to electrode surfaces may alter the rates of electrocatalytic reactions. Density functional theory (DFT) methods are used to predict the adsorption free energy of acetate and phosphate anions as a function of Pt(1 1 1) electrode potential. Four models of the electrode potential are used including a simple vacuum slab model, an applied electric field model with and without the inclusion of a solvating water bi-layer, and the double reference model. The linear sweep voltammogram (LSV) due to anion adsorption is simulated using the DFT results. The inclusion of solvation at the electrochemical interface is necessary for accurately predicting the adsorption peak position. The Langmuir model is sufficient for predicting the adsorption peak shape, indicating coverage effects are minor in altering the LSV for acetate and phosphate adsorption. Anion adsorption peak positions are determined for solution phase anion concentrations present in microbial fuel cells and microbial electrolysis cells and discussion is provided as to the impact of anion adsorption on oxygen reduction and hydrogen evolution reaction rates in these devices. |
| |
Keywords: | Anion adsorption Simulated LSV Density functional theory Microbial fuel cells Microbial electrolysis cells |
本文献已被 ScienceDirect 等数据库收录! |