华东理工大学李春忠团队报道了操纵H₂O₂电合成的表面活性剂-调制电极-电解质界面的机制见解。相关研究成果发表在2024年3月11日出版的《美国化学会杂志》。

在带电电极-电解质界面发生的电催化反应包含质子耦合电子转移过程。界面质子通过以H₂O为主的氢键网络传递到电极表面。从界面氢键网络的角度来看，对界面质子转移的调节作用较少。

该文介绍了季铵盐阳离子表面活性剂作为电解质添加剂，以提高氧还原反应（ORR）中H₂O₂的选择性。通过原位振动光谱和分子动力学计算，发现表面活性剂在给定的偏压范围内不可逆地吸附在电极表面，导致界面氢键网络减弱。

这降低了界面质子转移动力学，特别是在高偏压下，从而抑制4-电子ORR途径并实现对H₂O₂的高选择性2-电子途径。这些结果突出了通过调节界面氢键网络来引导涉及H₂O的电化学反应的机会。

附：英文原文

Title: Mechanistic Insights into Surfactant-Modulated Electrode–Electrolyte Interface for Steering H2O2 Electrosynthesis

Author: Yu Fan, Yuxin Chen, Wangxin Ge, Lei Dong, Yanbin Qi, Cheng Lian, Xiaodong Zhou, Honglai Liu, Zhen Liu, Hongliang Jiang, Chunzhong Li

Issue&Volume: March 11, 2024

Abstract: Electrocatalytic reactions taking place at the electrified electrode–electrolyte interface involve processes of proton-coupled electron transfer. Interfacial protons are delivered to the electrode surface via a H2O-dominated hydrogen-bond network. Less efforts are made to regulate the interfacial proton transfer from the perspective of interfacial hydrogen-bond network. Here, we present quaternary ammonium salt cationic surfactants as electrolyte additives for enhancing the H2O2 selectivity of the oxygen reduction reaction (ORR). Through in situ vibrational spectroscopy and molecular dynamics calculation, it is revealed that the surfactants are irreversibly adsorbed on the electrode surface in response to a given bias potential range, leading to the weakening of the interfacial hydrogen-bond network. This decreases interfacial proton transfer kinetics, particularly at high bias potentials, thus suppressing the 4-electron ORR pathway and achieving a highly selective 2-electron pathway toward H2O2. These results highlight the opportunity for steering H2O-involved electrochemical reactions via modulating the interfacial hydrogen-bond network.

DOI: 10.1021/jacs.3c13660

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.3c13660