Oxygen Reduction on Ag(100) in Alkaline Solutions—A Theoretical Study. Issue 4 (21st January 2016)

• Record Type: Journal Article
• Authors: Goduljan, Aleksej; de Campos Pinto, Leandro Moreira; Juarez, Fernanda; Santos, Elizabeth; Schmickler, Wolfgang
• Is Part Of: Chemphyschem. Volume 17:Issue 4(2016)
• Page Start: 500
• Page End: 505
• Publication Date: 2016-01-21
• Subjects: density functional calculations -- electrochemistry -- electron transfer -- oxygen -- silver; Chemistry, Physical and theoretical -- Periodicals; 541.05
• DOI: 10.1002/cphc.201501036
• Languages: English
• ISSNs: 1439-4235

Abstract

Abstract: Silver is much more reactive to oxygen than gold; nevertheless, in alkaline solutions, the rates of oxygen reduction on both metals are similar. To explain this phenomenon, the first, rate‐determining step of oxygen reduction on Ag(100) is determined by a combination of DFT, molecular dynamics, and electrocatalysis theory. In vacuum, oxygen is adsorbed on Ag(100), but in the electrochemical environment, the adsorption energy is offset by the loss of hydration energy as the molecule approaches the surface. As a result, the first electron transfer should take place in an outer‐sphere mode. Previously, the same mechanism for oxygen reduction on Au(100) has been predicted, and these calculations have been repeated by using a more advanced version of the electrocatalysis theory discussed herein to confirm previous conclusions. The theoretical results compare well with experimental data. Abstract : Mechanistic determination : The first, rate‐determining step of oxygen reduction on Ag(100) is determined by computational methods. In vacuum, oxygen is adsorbed on Ag(100), but in an electrochemical environment, the adsorption energy is offset by the loss of hydration energy as the molecule approaches the surface (see figure).