Decoupling the Hydrogen Binding Energy to the Hydrogen Oxidation Reaction Kinetics in Alkaline Media

Wednesday, 4 October 2017: 11:20
National Harbor 14 (Gaylord National Resort and Convention Center)
J. Li, S. Ghoshal, M. Bates, S. Mukerjee, and Q. Jia (Northeastern University)
The slow rate of the hydrogen oxidation reaction (HOR) at high pH environments remains as a most fundamental conundrum in electrochemistry. It also offsets recent advancements in alkaline membranes with applications to alkaline fuel cells and electrolyzers. Herein we challenge the current prevailing hydrogen binding energy (HBE) mechanism for the HOR in alkaline media by decoupling the HBE with the HOR kinetics of monometallic and bimetallic catalytic systems. By studying various Pt-Ru systems and Ru/C system with combined electrochemical and in situ spectroscopic methods, we suggest that the desorption of Hads is facilitated by the reactive OHads species furnished by surface Ru oxides via the bifunctional mechanism. Our results verify that the availability of metal oxides plays a critical role for the HOR kinetics for catalytic surfaces with high oxophilic sites.