Boosting mass and charge transport of anode catalyst layers in proton exchange membrane water electrolysis

Abstract

Membrane electrode assemblies (MEAs) are pivotal to advancing proton exchange membrane water electrolysis (PEMWE), yet conventional designs suffer from limited triple-phase boundaries (TPBs), inefficient mass/charge transport, and insufficient durability. This study introduces a three-dimensional ordered pattern-array (3D OPA) architecture fabricated via a scalable laser-machined mask and hot-pressing strategy. The 3D OPA MEA achieves a current density of 3.73 A cm⁻² at 2 V, demonstrating a 50 % performance improvement over the conventional MEA (2.48 A cm⁻²), alongside a degradation rate of 26.6 µV h⁻¹ in a highly dynamic accelerated stress test (AST). Additionally, numerical simulations corroborate that the OPA architecture optimizes localized oxygen diffusion and liquid water replenishment, enhancing reaction kinetics. The 3D OPA architecture enhances TPBs and establishes optimized gas-liquid transport pathways, significantly improving catalyst utilization while minimizing mass transfer overpotential and bubble-induced losses. Furthermore, its interlocking design reinforces mechanical interactions, reducing ohmic resistance and ensuring sustained mechanical integrity and electrochemical durability. This work provides a simple, cost-effective, and scalable approach for patterned MEAs, addressing critical barriers to PEMWE commercialization through rational TPB engineering and transport pathway optimization.