Taming N2 Bubbles with Immiscible Droplets for Stable Hydrazine Electrooxidation.

Abstract

Gas bubble accumulation at electrode surfaces remains a major challenge in gas-evolving electrocatalytic reactions because it blocks active sites, hinders mass transport, and can ultimately shut down electrochemical turnover. Here, we show that introducing immiscible 1,2-dichloroethane (DCE) microdroplets at the electrode interface redirects electrogenerated N2 from hydrazine oxidation, preventing direct accumulation at the electrode|electrolyte boundary, without requiring complex surface redesign. This liquid microenvironment suppresses early bubble nucleation, interrupts lateral coalescence, delays transport-limited failure, and preserves long-term interfacial accessibility. The resulting stabilization arises from dynamic gas uptake, redistribution, and release through the organic phase. As a result, the modified interface remains electrochemically active during prolonged operation, whereas the unmodified system undergoes severe deactivation because of macroscopic bubble insulation. These findings establish immiscible microdroplet-based microenvironment engineering as an effective strategy for stabilizing gas-evolving electrocatalytic reactions.