Oxygen Evolution Reaction at Carbon Edge Sites: Investigation of Activity Evolution and Structure-Function Relationships with Polycyclic Aromatic Hydrocarbons

Angew Chem Int Ed Engl. 2019 Jun 24;58(26):8917-8921. doi: 10.1002/anie.201902884. Epub 2019 May 17.

Abstract

The abundance of available surface chemical information and edge structures of carbon materials have attracted tremendous interest in catalysis. For the oxygen evolution reaction (OER), the edge effects of carbon materials have rarely been studied in detail because of the complexity of various coexisting edge configurations and the controversy between carbon corrosion and carbon catalysis. Herein, the exact roles of common carbon active edge sites in the OER were interrogated using polycyclic aromatic hydrocarbons (PAHs) with designated configurations (zigzag and armchair) as model probe molecules, with a focus on structure-function relationships. Zigzag configurations of PAHs showed high activity for the OER while also showing a good stability at a reasonable potential. They show a TOF value of 0.276 s-1 in 0.1 m KOH. The catalytic activity of carbon edge sites was further effectively regulated by extending the π conjugation structure at a molecular level.

Keywords: OER; carbon materials; edge sites; isotope effect.