Modelagem multiescala e validação experimental da dinâmica interfacial em sistemas de eletrólise da água: explorando fenômenos locais inerentes das reações eletroquímicas

Abstract

This thesis addresses the efficiency challenges in hydrogen production via water electrolysis, focusing on the coupled effects of gas bubble evolution and interfacial pH variations during alkaline electrolysis. Multiscale computational models were developed, combining the Finite Element Method (FEM) and Computational Fluid Dynamics (CFD) to simulate bubble dynamics and interfacial pH distribution, with experimental validation using filming techniques and chronopotentiometric analysis to explore energy consumption during electrolysis. The results showed that pulsed-current operation can mitigate local pH variations; however, maintaining stable pH conditions under high current densities remains a challenge. Additionally, an asymmetric electrolysis cell configuration was proposed and validated, demonstrating a reduction in local pH gradients and up to a 17% improvement in electrolysis efficiency. This work opens new perspectives for developing more efficient electrolyzers, contributing to sustainable and economically viable hydrogen production.