High-performance microfluidic electrochemical reactor for efficient hydrogen evolution

Hydrogen production from water electrolysis provides an effective bridge between the existing energy system and the layout of green renewable energy. Electrochemical hydrogen gas evolution on the electrode surface will occupy the limited active sites thus significantly increasing the reaction overpotential. It is crucial to study and optimize the bubble behavior on the electrode surface to improve reaction efficiency and lower the energy loss. Herein, a microfluidic electrochemical reactor (MER) has been constructed to optimize the surface gas-liquid two-phase flow behavior during the gas evolution process. The obtained results demonstrate the feasibility of microfluidic design in manipulating the bubble behavior at the electrode interface accompanied with the self-generated gas-liquid two-phase flow, which can directly reduce the overpotentials by facilitating the mass transfer and refreshing catalytic active sites. Compared with conventional H-cell, state-of-the-art efficient and stable performance of hydrogen evolution has been achieved, where the increase in current density was more than 5 times. This work reveals a new strategy for guiding the design of the electrochemical reactor for water splitting.