High Performance Porous Transport Electrodes for Polymer Electrolyte Membrane Water Electrolysis
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2025-07-11 |
| Journal | ECS Meeting Abstracts |
| Authors | Abhay Gupta, Leila Moradizadeh, Samaneh Shahgaldi |
Abstract
Section titled âAbstractâGreen hydrogen as renewable energy source has garnered a lot of attention in the contemporary world where decarbonization is of utmost priority [1]. Compared to conventional renewable resources of energy like solar, wind, and water, green hydrogen provides a reliable and consistent way of energy storage, transportation, and utilization [2]. While alkaline electrolysis is the most matured technology for green hydrogen production, the poor operational efficiencies still create a bottleneck in its widespread acceptance. On the other hand, polymer electrolyte membrane water electrolysis (PEMWE) offers high operational efficiency with a compact design [3]. The underlying difficulty in promoting the PEMWE technology lies in the requirement of platinum and iridium for the PEMWE components [4]. Hence, consistent efforts have been made in minimizing and recycling the Ir-based catalyst. A typical PEMWE single cell consists of (i) a proton conducting perfluorinated sulphonic acid based polymer electrolyte membrane (PEM) with anode and cathode catalyst layer on either side, (ii) a Ti-based porous transport layer (PTL) on the anode side for water distribution and oxygen passage through its pores, electronic conduction through its bulk, and mechanical support to the membrane, (iii) a carbon-based gas diffusion layer on the cathode side for hydrogen passage and electronic conduction, and (iv) metallic bipolar plates which provide flow channel for water, oxygen (on anode side) and hydrogen (on cathode side) and current collection. A catalyst layer can either be deposited on the membrane surface or on the PTL/GDL surface. In the former case, the catalyst layer can directly be deposited by catalyst coated membrane (CCM) methodology or using an intermediate decal transfer method (DTM) [5]. hile the CCM methodology ensures an excellent proton transfer channel, it simultaneously creates difficulties in the catalyst recycling and minimizing the ohmic overpotential losses [6]. Researchers have introduced anode porous transport electrode (PTE) configurations where the Ir-based catalyst is deposited on the PTL directly and it ensures corrosion resistance of PTL, high electronic conductivity, low catalyst utilization and catalyst recovery. Liu et al. [7] developed PTE configurations for PEMWE; however, they did not observe the PEMWE cell characteristics comparable to the CCM configurations and they attributed the low performance to the poor catalyst distribution on the PTL. Lee et al. [8] created rough PTL surface using laser ablation and reported improved PEMWE cell characteristics. In this work, we have introduced a novel approach for fabricating PTE configuration using electroplated Pt on the PTL which ensured high specific surface area for the Ir-based catalyst deposition. Pt deposit morphology was optimized by varying the electroplating conditions and Ir-based catalyst was spray coated directly on the electroplated PTLs. The duration of electroplating was varied between 5 to 60 minutes. The corresponding SEM micrographs are presented in Figure 1. Evidently, in Figure 1(d), high roughness was introduced in the S3 sample because of the electroplated Pt on the PTL surface. The in-situ PEMWE cell testing was performed with each PTE sample and compared with the conventional CCM configuration. Figure 1(e) shows the polarization plots generated after compensating the high frequency resistance obtained from electrochemical impedance spectroscopy analysis. In the HFR-free polarization plots, it was observed that the CCM and S3 samples performed much better than the S1 and S2 samples. At 2.0 A/cm 2 , the output HFR-free voltage for CCM, S1, S2, and S3 sample was 1.56 V, 1.61 V, 1.61 V, and 1.57 V, respectively. The results of this study showed that the appropriate surface modifications on the PTL surface can facilitate a PTE configuration with high PEMWE performance. Figure 1: Representative SEM morphological micrographs for (a) uncoated PTL for CCM sample, (b) S1 sample, (c) S2 sample, (d) S3 sample, and (e) HFR-free PEMWE cell polarization curves for the membrane electrode assembly fabricated using the CCM method (black square) and PTE method (S1 - red circle, S2 - green triangle, and S3 - yellow diamond). References: [1] S.R. Mishra, et al. , Nano Energy 128 (2024) 109820. [2] X.C. Schmidt Rivera, et al., J Clean Prod 196 (2018) 863-879. [3] F. Barbir, Solar Energy 78 (2005) 661-669. [4] L. Wang, et al., Nano Energy 34 (2017) 385-391. [5] S. Shahgaldi, et al. Int J Hydrogen Energy 42 (2017) 11813-11822. [6] M. BĂźhler, et al. J Electrochem Soc 166 (2019) F1070-F1078. [7] C. Liu, et al. ACS Appl Mater Interfaces 13 (2021) 16182-16196. [8] J.K. Lee, et al. Nature Communications 2023 14:1 14 (2023) 1-11. Figure 1