Kim, Jae-Hun Lee, Hye Jin Lee, Soo Youn Noh, Min Su Shin, Eun Jeong Jung, Hwi Jong Kim, Yuri Park, Hee-Young Kim, Hee Soo Lee, Jiye Lee, Eunjik Kan, Eunsung Jang, Jong Hyun Kim, Hyoung-Juhn Woo, Sahng Hyuck 2025-07-30T06:00:07Z 2025-07-30T06:00:07Z 2025-07-28 2025-09 1385-8947 https://pubs.kist.re.kr/handle/201004/152886 This study investigates the modification of halloysite nanotubes (HNTs) through sulfonation to enhance their performance as catalytic support materials in proton exchange membrane water electrolyzer (PEMWE) anodes. Sulfonated HNTs (S-HNTs) exhibited improved dispersion and proton transport due to the incorporation of sulfonic acid groups (10.23 x 10-5 mol/g) and reduced particle size. FTIR, XRD, thermal analysis, and TEM confirmed the successful modification, demonstrating enhanced stability and morphology. The MEA incorporating 10 wt% S-HNT01 in the anode achieved a high current density of 3.2 A cm- 2 at 1.8 V, meeting the 2026 US DoE performance target. Additionally, with a reduced IrO2 loading of 0.2 mg cm- 2, the mass activity reached 8.75 A mg-1, significantly improving catalytic efficiency while minimizing precious metal usage. Long-term testing confirmed better durability compared to unmodified HNTs. These findings demonstrate that S-HNT01 enhances the efficiency, durability, and cost-effectiveness of PEMWE, making it a promising candidate for advanced water electrolysis applications. English Elsevier BV Advanced catalytic support materials featuring polymeric short-side chains for PEM water electrolysis anodes Article 10.1016/j.cej.2025.164773 1 Chemical Engineering Journal, v.519 Chemical Engineering Journal 519 N scie scopus 001519369300030 2-s2.0-105008445525 Engineering, Environmental Engineering, Chemical Engineering Article PROTON CONDUCTIVITY MEMBRANE NANOTUBES Anode Catalytic support materials Halloysite nanotube (HNT) Proton exchange membrane water electrolysis (PEMWE)