Boron–Sulfur Pairs for Highly Active 2e<sup>–</sup> Oxygen Reduction Reaction to Electrochemically Synthesize Hydrogen Peroxide
Yuhan Wu, Qixin Yuan, Yuying Zhao, Xiang Xu, Jing Xu, Yan Wang, Kang Sun, Ao Wang, Hao Sun, Bei Li, Ruting Xu, Zeming Wang, Jianchun Jiang, Mengmeng Fan
Abstract
Past decade has witnessed the great improvement of carbon-based dual-single metal-site electrocatalysts. However, there are rare reports exploring the enhanced effect of a nonmetallic “dual-site” in carbon-based catalysts. Herein, a “H 3 BO 3 template” method is proposed to fabricate highly active B–S pairs dispersed on a hierarchically microporous/mesoporous carbon matrix to electrochemically synthesize hydrogen peroxide by two-electron oxygen reduction reaction. Under the synergistic effect of B–S pairs and advantageous nanostructures, the catalytic performance outperforms the reported metal-free carbon catalysts in alkaline electrolytes, especially, with a high HO 2 – selectivity of 90–94% at a wide potential range of 0.3–0.7 V versus reversible hydrogen electrode (RHE) using a rotating ring-disk electrode, Faradaic efficiency of over 90% during 11 h stability testing, and high mass activity of 756 mmol g catalyst –1 h –1 in a flow cell. Density functional theory demonstrates that the carbon atoms nearby B–S pairs exhibit predominant catalytic sites. This paper proposes a new approach to distinctly improve the catalytic performance by dual heteroatom pairs.