Enhanced production of hydrogen from alkaline electrolysis by microbubbles removal on bionic electrode

Abstract

In this paper, a plane electrode reactor with gas electro-generation in alkaline water electrolysis was developed. In such electrochemical reactors, the efficiency is closely linked to the hydrodynamics of the electrogenerated bubbles acting as movable electrical insulators. The electric and flow fields of the electrodes were studied by numerical simulation methods and the data revealed even electric potential distributions of the novel bionic type when compared to conventional grid type. The Murray leaf-like total pressure drop was the lowest and the flow field was mostly uniform, resulting in synergetic effect of electric field and flow field with higher hydrogen concentration reaching about 50% the traditional one. The experimental data indicated lower overpotential of Murray leaf-like structure by 12% than those obtained by traditional grid electrode plates. Furthermore, the visual experiments showed that the mean bubble size of the bionic leaf-like electrodes was smaller than that of the grid type by 45%, suggesting possible optimization of generated and detachment of hydrogen bubbles on the bionic electrode surface. In sum, the combination of uniform current distribution and efficient removal of hydrogen bubbles by optimizing the electrodes through bionic design could promote the efficiency of the alkaline water electrolysis for hydrogen production.