Hydrophobicity engineering of hierarchically ordered SiO 2 /Fe-N-C catalyst with optimized triple-phase boundary for boosting oxygen reduction reaction

作者：Yang Zhang, Bingbing Gong, Benji Zhou, Zhibo Liu, Nengneng Xu, Yongxia Wang, Xiaoqian Xu, Qing Cao, Daniil I. Kolokolov, Haitao Huang, Shuaifeng Lou, Guicheng Liu, Woochul Yang, Jinli Qiao · 发表于：Nano Research Energy · 年份：2025 · DOI：10.26599/nre.2025.9120180 · 被引用次数：13 · 研究领域：Electrocatalysts for Energy Conversion、Fuel Cells and Related Materials、Catalysis and Hydrodesulfurization Studies

The Fe single-atom catalyst (Fe-N-C) with Fe-N x active sites is considered a promising alternative to Pt-based catalysts for oxygen reduction reaction (ORR). However, the exposure and utilization efficiency of the Fe-N x site in Fe-N-C leads to a certain competitive distance with Pt-based catalysts in the ORR process. Herein, a space-confinement strategy triggered by SiO 2 templates to optimize the ORR triple-phase boundary of Fe-N-C, is reported. As expected, the optimized SiO 2 (4)/Fe-N-C exhibits excellent ORR activity with a half-wave potential of 0.886 V in 0.1 M KOH. More importantly, the E 1/2 loss of SiO 2 (4)/Fe-N-C is merely 32 mV after 30,000 cycles. Density functional theory (DFT) calculations confirm SiO 2 -induced carbon defects critically modulate electronic configurations of FeN 4 centers, optimizing adsorption energetics of oxygen intermediates. Remarkably, when utilized as air cathodes for zinc-air batteries (ZABs), the device based on SiO 2 (4)/Fe-N-C displays record-breaking power density (444.10 mW·cm –2 ) with superior long-term durability over 1013 h, outperforming most reported noble-metal-free electrocatalysts. This work provides a new route to optimize the triple-phase boundary of single-atom catalysts for energy storage applications.