Electrochemical hydrogen gas evolution on the electrode surface will occupy the limited active sites thus significantly increases the reaction overpotential. It is crucial to study and optimize the bubble behavior on the electrode surface to improve the reaction efficiency and lower the energy loss. Herein, a microfluidic electrochemical reactor (MER) was constructed to optimize the surface kinetic behavior during the gas evolution process. The obtained results demonstrate the feasibility of microfluidic design in manipulating the bubble behavior at the electrode interface through the self-generated gas-liquid two-phase flow, which can simultaneously reduce the overpotential and facilitate the mass transfer. Compared with the traditional H-cell, the hydrogen evolution efficiency can present a remarkable intensification. Our work reveals a new strategy for guiding the design of the electrochemical reactor for water splitting.
Keywords Electrochemical water splitting, Microfluidic reactor, Mass transfer, Two-phase flow, Bubble behavior