A Universal Picture of the HER/HOR Kinetics of Pt in Alkaline Solution
Abstract
Some progress has been recently made in understanding the sluggish kinetics of hydrogen evolution and oxidation reactions (HER/HOR) of Pt in alkaline solutions. The pH dependence of the HER/HOR activity of Pt was reasonably accounted for by the potential of zero free charge (pzfc) theory.1 We lately proposed the 2B theory to account for the alkali cation effects on the HER/HOR activity of Pt and the beneficial roles of the second metal such as the Ni on the HER/HOR activity of Pt.2,3 Meanwhile, the Ru-induced improvement of the HOR activity of Pt was ascribed to the bifunctional mechanism4,5 or the hydrogen binding energy.6,7 However, these different theories often conflict with each other, and have not been unified into a coherent picture depicting the kinetics of HER/HOR in alkaline solutions. Herein, we propose a new theory to account for the Ni and Ru induced improvement of the HOR activity of Pt in alkaline solutions, on the basis of combined electrochemical and in situ spectroscopic data. The combination of this new theory with the pzfc and 2B theories appears to give a coherent picture of the HER/HOR kinetics of Pt in alkaline solutions.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Sep 01, 2019
- Source ID
- 10.1149/ma2019-02/36/1669
Entities
People
- Ershuai Liu
- Li Jiao
- Qingying Jia
- Sanjeev Mukerjee