Se‐Assisted Modulation of Electronic Structure of Ruthenium Phosphide Nanotubes for Efficient Alkaline Hydrogen Evolution Reaction
Yongju Hong, Eunsoo Lee, Jae Hun Seol, Tae Kyung Lee, Songa Choi, Seong Chan Cho, Taekyung Kim, Hionsuck Baik, Sangyeon Jeong, Sung Jong Yoo, Sang Uck Lee, Kwangyeol Lee
Abstract
Anion‐exchange membrane water electrolysis (AEMWE) holds immense promise for hydrogen (H 2 ) production yet faces challenges due to the sluggish kinetics of the hydrogen evolution reaction (HER). Highly efficient and durable catalysts for HER are crucial for the successful implementation of AEMWE to produce hydrogen gas reliably. Ruthenium phosphides (Ru x P) have emerged as promising non‐Pt catalysts for alkaline HER; however, they suffer from rapid degradation due to weak RuP bonding, which cannot protect the Ru center from further oxidation and subsequent dissolution. Herein, first‐principles calculations indicate the enhanced stability of RuSe against oxidation compared to RuP, highlighting the importance of introducing Se into the Ru 2 P phase. Electrochemical studies using the selenium (Se)‐doped Ru 2 P double‐walled nanotubes (Ru 2 (P 0.9 Se 0.1 ) DWNTs) demonstrate significantly lower overpotentials (29 mV @ 10 mA cm −2 ) and robust stability (>50 h) in 1.0 m KOH, surpassing those of Pt/C. In AEMWE, Ru 2 (P 0.9 Se 0.1 ) DWNTs exhibit an outstanding performance (10.31 A cm −2 @ 80 °C, stable @ 1.0 A cm −2 for ≈200 h), surpassing state‐of‐the‐art catalysts. The findings of this study highlight the pivotal role of anion modification in enhancing the catalytic stability and performance for efficient hydrogen production in AEMWE systems.