Advances in Anode Porous Transport Layer: Structural Design and Coating Strategy for Efficient Proton Exchange Membrane Water Electrolyzer

Abstract

The anode porous transport layer (PTL) is crucial in proton exchange membrane water electrolyzers (PEMWEs), facilitating efficient mass transport, electron conduction, and heat dissipation. This paper reviews advancements in PTL structural design and coating strategies, emphasizing their impact on cell performance, durability, and cost-effectiveness. The acid resistance of Ti-based PTLs has led to their widespread adoption; nonetheless, challenges such as increased ohmic resistance and catalyst delamination caused by oxidation to TiO2 remain. A comprehensive investigation into the relationship between PTL pore structure and PEMWE performance has yielded significant advancements, including gradient porosity design, optimized pore structures, as well as thin and planar PTLs. Furthermore, anti-corrosion coatings, predominantly comprising precious metal layers such as Pt and Ir, have enhanced durability and performance. However, high costs pose significant constraints, prompting the exploration of non-precious material alternatives, including Nb, Ti, and Ta. In addition, the emergence of porous transport electrodes has facilitated cost-effective, high-performance PEMWE systems by integrating the dual-functional roles of catalytic activity and corrosion prevention. This paper provides key insights into designing cost-effective and high-performance PTLs to support the future hydrogen economy.