质谱技术在固-液界面电化学中间产物探测中的研究进展

Recent Advances in Detection of Electrochemical Reaction Intermediates at the Solid-Liquid Interface by Mass Spectrometry

电化学反应过程中,固-液界面瞬态中间体的快速捕获与实时监测对研究电化学反应机理具有重要意义。质谱具有灵敏度高、特异性强等优点,能够提供待测物的组成与结构信息,已逐渐成为电化学反应中间体检测的有力工具。本文综述了基于电喷雾质谱、原位电离质谱以及飞行时间二次质谱的电化学质谱(EC-MS)联用技术在电化学反应瞬态中间体检测方面的研究进展,系统地总结了EC-MS在有机电合成、电催化、锂离子电池、电致化学发光以及生物分子电化学反应过程分析等领域的应用情况,并对质谱技术在电化学反应中间体检测方面面临的挑战和发展趋势进行展望。

Electrochemical reaction is a continuous dynamic process,accompanied by electron transfer and generation of short-lived intermediates.The mechanism investigation of electrochemical interfaces is pivotal for the progression of energy storage,electro-organic synthesis,electrocatalysis,and electroanalysis.The valuable insights for optimizing performance,improving efficiency,and developing novel methodologies can be attained by elucidating the complicated pathways involved in the electrochemical processes.Thus,how to monitor transient intermediates formed at the solid-liquid interface becomes the critical point in unraveling these intricate processes.To this end,a series of in-situ analytical methods such as in-situ electron paramagnetic resonance spectroscopy(in-situ EPR),in-situ Raman spectroscopy,in-situ infrared spectroscopy(in-situ IR)and in-situ electrochemical mass spectrometry(in-situ EC-MS)have been exploited to probe the chemical transformations at the electrode/electrolyte interface.Among them,due to the superior specificity for interpreting molecular information,EC-MS has progressively gained extensive attention as a powerful and reliable tool for capturing intermediates and revealing the mechanisms in electrochemical reactions.In this review,the research progresses in the recent advancements in the detection of transient reaction intermediates through electrochemical mass spectrometry were presented.The discussion centered on elucidating the principle and configuration of the devices employed in EC-MS,with a specific focus on electrospray ionization mass spectrometry(ESI-MS),atmospheric pressure ionization mass spectrometry(AIMS)and time-of-flight secondary ion mass spectrometry(TOF-SIMS).In addition,the review delved into the wide-ranging applications of EC-MS in monitoring electrochemical processes in electro-organic synthesis,electrocatalysis,lithium-ion batteries,electrochemiluminescence,and bioelectrochemical reactions.Despite the remarkable progress has made,the challenges in the field of EC-MS are prospected.There is still an urgent need for further improvement of the experimental apparatus to enhance the sampling efficiency and time resolution to capture short-lived and low-concentration reaction intermediates.In the future,we anticipate that EC-MS will be combined with other in situ analytical techniques,such as in situ infrared or Raman spectroscopy,enabling multi-dimensional characterization and monitoring of electrochemical reaction intermediates.