Real-time detection of sub-monolayer desorption phenomena during electrochemical reactions: Instrument development and applications
A microfabricated membrane chip enables direct, loss-free coupling between wet electrochemistry and a mass spectrometer vacuum — delivering higher sensitivity than conventional DEMS with no compromise on response time. The system achieves 100% collection efficiency and sub-monolayer detection, and is used to uncover a new CO reduction pathway on copper: pre-exposure to dioxygen temporarily enables enhanced methane production, explained via DFT as an oxygen-induced geometric effect at kink sites.