Presentation Information
[3H13]Determination of Reaction Order and Rate-Determining Step in Oxygen Reduction Reaction on Nitrogen-Doped Carbon Catalysts
*Kaito Homma1, Kenji Hayashida2, Bang Lu1, Satoru Takakusaki1, Kotaro Takeyasu1 (1. Hokkaido University, 2. Tsukuba University)
Nitrogen-doped carbon materials have attracted considerable attention as non-metallic alternatives to platinum catalysts for the oxygen reduction reaction (ORR). While we have previously synthesized highly active nitrogen-doped carbon catalysts, their activity remains lower than that of platinum-based catalysts. To guide further improvements, it is crucial to understand the underlying reaction mechanism. In this study, we aimed to identify the rate-determining step in the ORR by determining the reaction order. By measuring the dependencies of the reaction rate on oxygen concentration and proton concentration, as well as the pKa, it was revealed that the rate-determining step on the highly active nitrogen-doped graphene catalyst is the adsorption of oxygen molecules coupled with electron transfer.