Simultaneous Capture and Profile the Kinetic Changes of Short-Lived Reactive Electrochemical Reaction Intermediates by Time-Resolved Mass Spectrometry

The mechanistic studies of electrosynthetic reactions are challenged by the effective characterization of the elusive intermediate processes. Here, we develop a new mass spectrometry-based on-line platform that integrates functionalized electrochemical microreactor with nano-electrostatic spray ionization system to simultaneously capture short-lived intermediates and profile their real-time changing processes. The independent electrochemical module allows the reaction modes to be freely transformed to maximize the simulation of real electrosynthetic process. Using this platform, the mechanistic studies of classic electrooxidation and complex multi-step paired electrosynthesis reactions were realized. The key electrochemical reaction intermediates of C−O/O−H cross-metathesis and their kinetic changes were successfully captured and profiled in both direct current and alternating current modes, providing direct evidence and deep insights on the reaction mechanism.