Steering <i>sp</i>‐Carbon Content in Graphdiynes for Enhanced Two‐Electron Oxygen Reduction to Hydrogen Peroxide
Ying Guo, Rong Zhang, Shaoce Zhang, Hu Hong, Pei Li, Yuwei Zhao, Zhaodong Huang, Chunyi Zhi
Abstract
Abstract Compared to sp 2 ‐hybridized graphene, graphdiynes (GDYs) composed of sp and sp 2 carbon are highly promising as efficient catalysts for electrocatalytic oxygen reduction into oxygen peroxide because of the high catalytic reactivity of the electron‐rich sp ‐carbon atoms. The desired catalytic capacity of GDY, such as catalytic selectivity and efficiency, can theoretically be achieved by strategically steering the sp ‐carbon contents or the topological arrangement of the acetylenic linkages and aromatic bonds. Herein, we successfully tuned the electrocatalytic activity of GDYs by regulating the sp ‐to‐ sp 2 carbon ratios with different organic monomer precursors. As the active sp ‐carbon atoms possess electron‐sufficient π orbitals, they can donate electrons to the lowest unoccupied molecular orbital (LUMO) orbitals of O 2 molecules and initiate subsequent O 2 reduction, GDY with the high sp ‐carbon content of 50 at % exhibits excellent capability of catalyzing O 2 reduction into H 2 O 2 . It demonstrates exceptional H 2 O 2 selectivity of over 95.0 % and impressive performance in practical H 2 O 2 production, Faraday efficiency (FE) exceeding 99.0 %, and a yield of 83.3 nmol s −1 cm −2 . Our work holds significant importance in effectively steering the inherent properties of GDYs by purposefully adjusting the sp ‐to‐ sp 2 carbon ratio and highlights their immense potential for research and applications in catalysis and other fields.