| 초록 |
Ni-based catalysts have been widely studied as promising alternatives to Pt group metal catalysts in anion exchange membrane water electrolysis. However, their insufficient durability at the membrane electrode assembly (MEA) poses a significant limitation. In this study, we evaluated the performance and durability of Ni3Mo, PtNi/ C, and Pt/C catalysts in MEAs under various intermittent protocols that mimic electricity production from renewable energy sources. In the intermittent protocols, sets of open circuit voltage (OCV) and constant current densities of 0.1 A cm(-2) and/or 1 A cm(-2) with different duration times were repeated for overall test time of 165 h. The Ni3Mo catalyst demonstrated severe degradation in cell performance for the long OCV duration of 1 h, while shorter exposure of 1 or 30 min presented little degradation, although the metal dissolution still occurred significantly. The cell degradation mainly resulted from phase transformation of the metallic Ni3Mo to Ni(OH)(2). The Pt/C catalyst showed substantial degradation in the cell performance when the current density was frequently changed with short duration (1 min) at OCV, resulting from the Pt aggregation. The PtNi/C presented the most stable cell performance under various intermittent protocols, due to the formation of surface Ni hydroxide species that inhibit aggregation. The changes in the overpotentials at cathode, membrane, and anode were further investigated using 3-electrode MEA system. The PtNi/C catalysts were synthesized with various compositions of Pt:Ni ratios, and also the Pt1Ni1/C catalysts were synthesized with various sizes, but the effect of composition and sizes were insignificant for the cell performance.
|
GISCIENCE & REMOTE SENSING, v.63, no.1, 2026-12