Approaching Theoretical Performances of Electrocatalytic Hydrogen Peroxide Generation by Cobalt‐Nitrogen Moieties
Runjia Lin, Liqun Kang, Karolina Lisowska, Weiying He, Siyu Zhao, Shusaku Hayama, Graham J. Hutchings, Dan J. L. Brett, Furio Corà, Ivan P. Parkin, Guanjie He
Abstract
Abstract Electrocatalytic oxygen reduction reaction (ORR) has been intensively studied for environmentally benign applications. However, insufficient understanding of ORR 2 e − ‐pathway mechanism at the atomic level inhibits rational design of catalysts with both high activity and selectivity, causing concerns including catalyst degradation due to Fenton reaction or poor efficiency of H 2 O 2 electrosynthesis. Herein we show that the generally accepted ORR electrocatalyst design based on a Sabatier volcano plot argument optimises activity but is unable to account for the 2 e − ‐pathway selectivity. Through electrochemical and operando spectroscopic studies on a series of CoN x /carbon nanotube hybrids, a construction‐driven approach based on an extended “dynamic active site saturation” model that aims to create the maximum number of 2 e − ORR sites by directing the secondary ORR electron transfer towards the 2 e − intermediate is proven to be attainable by manipulating O 2 hydrogenation kinetics.