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

• Published in: Angewandte Chemie International Edition Vol. 58; no. 26; pp. 8917 - 8921
• Main Authors: Lin, Yangming, Lu, Qing, Song, Feihong, Yu, Linhui, Mechler, Anna K., Schlögl, Robert, Heumann, Saskia
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 24.06.2019; John Wiley and Sons Inc
• Edition: International ed. in English
• Subjects: Carbon; carbon materials; Catalysis; Catalytic activity; Communication; Communications; Configurations; Conjugation; Edge effect; edge sites; Evolution; isotope effect; Molecular structure; OER; Organic chemistry; Oxygen; Oxygen evolution reactions; Polycyclic aromatic hydrocarbons; Structure-function relationships; carbon materials; isotope effect; OER; edge sites
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201902884

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. The active roles of the armchair and zigzag edge sites of carbon materials in the electrochemical oxygen evolution reaction (OER) have been investigated by using polycyclic aromatic hydrocarbons with designated configurations as active edge probes. Zigzag motifs play a more positive role in the OER. The underlying structure–function relationships could be further established by extending the exposed zigzag units.