Enhancement of hydrogen production via optimizing micro-structures of electrolyzer on a microfluidic platform

Abstract

Electrochemical water splitting plays a vital role for production of hydrogen (H2). Enhancing the rate of hydrogen separation from the electrode is crucial for improving the performance of water electrolyzers. The water electrolyzers often encounter issues such as air bubble adhesion to the electrode plate, leading to increased electrical resistance, reduced current density, and thus lower hydrogen generation rates. In addition, the compact configuration of electrolyzer and non-transparent electrode plates make it impracticable to observe and analyze the gas-liquid two-phase flow between the anode and cathode plates. Hence, a methodology is in high demand to experimentally investigate the two-phase flow within the electrolyzer, which could be further used to guide the design and optimization of the electrolyzer. In this work, we propose to utilize a microfluidic system as a phantom of electrolyzer. The transparent material of the microfluidic chip allows optical inspection and measurement of the two-phase flow. Specifically, we propose to optimize the two-phase flow by manipulating the micro-structure of the flow, which has been theoretically and experimentally demonstrated to effectively remove the gas bubbles attached to the wall and consequently enhance the hydrogen production rate. The dimensions of the proposed micro-structures can be potentially extended and applied to industrial electrolyzers according to the principle of similarity.