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Vol. 17 (2025)

Triple-Layer Porous Transport Layers with Ultra-High Porosity for Enhanced Oxygen Transport and Catalyst Utilization in Water Electrolysis

https://doi.org/10.1007/s40820-025-01831-z
Seong Hyun Park
Department of Mechanical Engineering, KAIST, Daejeon 34141, Republic of Korea
Young Je Park
Department of Mechanical Engineering, KAIST, Daejeon 34141, Republic of Korea
Seungsoo Jang
Department of Mechanical Engineering, KAIST, Daejeon 34141, Republic of Korea
Pilyoung Lee
Hydrogen and Fuel Cell Development Center, Hyundai Motor Group, Gyeonggi‑do 16891, Republic of Korea
Soobin Yoon
Hydrogen and Fuel Cell Development Center, Hyundai Motor Group, Gyeonggi‑do 16891, Republic of Korea
Young‑June Park
Hydrogen and Fuel Cell Development Center, Hyundai Motor Group, Gyeonggi‑do 16891, Republic of Korea
Chi‑Young Jung
Hydrogen Research and Demonstration Center, Hydrogen Energy Institute, Korea Institute of Energy Research (KIER), Jeollabuk‑do 56332, Republic of Korea
Kang Taek Lee
Department of Mechanical Engineering, KAIST, Daejeon 34141, Republic of Korea

Corresponding Author: Kang Taek Lee

leekt@kaist.ac.kr

Nano-Micro Letters, Vol. 17 (2025), Article Number: 316

Abstract

The commercialization of proton exchange membrane water electrolysis (PEMWE) for green hydrogen production hinges on the development of low-cost, high-performance titanium porous transport layers (PTLs). This study introduces a triple-layer Ti-PTL with a graded porous structure and a 75% ultra-high porosity backing layer, fabricated through tape casting and roll calendering. This triple-layer PTL, composed of a microporous layer, an interlayer, and a highly porous backing layer, enhances catalyst utilization, mechanical integrity, and mass transport. Digital twin technology using X-ray revealed increased contact area and triple-phase boundary at the interface with the catalyst layer, significantly improving oxygen evolution reaction kinetics. Numerical simulations demonstrated that the strategically designed porous structure of the triple-layer PTL facilitates efficient oxygen transport, mitigates oxygen accumulation, and improves reactant accessibility. Electrochemical evaluations showed improved performance, achieving 127 mV reduction in voltage at 2 A cm−2 compared to a commercial PTL, highlighting its potential to enhance PEMWE efficiency and cost-effectiveness.


Highlights:
1 A novel triple-layer Ti-porous transport layer (PTL), fabricated using a practical and scalable tape casting and roll calendering process, enhances catalyst utilization by increasing interfacial contact area and the triple-phase boundary.
2 The ultra-high porosity (75%) backing layer and graded structure maximize oxygen transport, mitigate oxygen accumulation, and improve reactant accessibility.
3 Electrochemical evaluations demonstrate a 127 mV reduction in voltage at 2 A cm−2 compared to a commercial PTL, accelerating proton exchange membrane water electrolysis commercialization and supporting the transition to sustainable energy.

Keywords

Proton exchange membrane water electrolysis Porous transport layer Catalyst utilization Mass transport Digital twin
Park, Seong Hyun, Young Je Park, Seungsoo Jang, Pilyoung Lee, Soobin Yoon, Young‑June Park, Chi‑Young Jung, and Kang Taek Lee. 2025. “Triple-Layer Porous Transport Layers With Ultra-High Porosity for Enhanced Oxygen Transport and Catalyst Utilization in Water Electrolysis”. Nano-Micro Letters 17 (June):316. https://doi.org/10.1007/s40820-025-01831-z.
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