Driving Adsorbate Evolution via Oxygenated Surface Species Modulation for Ammonia Electrooxidation
Kim, Jeongwon Hang, Yucheng Park, Hyundo Cheng, Linlin Gong, Mingming Shah, Aamir Hassan Shin, Heejong Ye, Caichao Kim, Dong Ha Bu, Yunfei
Kim, Jeongwon
Hang, Yucheng
Park, Hyundo
Cheng, Linlin
Gong, Mingming
Shah, Aamir Hassan
Shin, Heejong
Ye, Caichao
Kim, Dong Ha
Bu, Yunfei
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Department
Machine Learning
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Journal article
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English
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Abstract
The electrochemical ammonia oxidation reaction (eAOR) to dinitrogen offers a promising pathway for sustainable nitrogen cycles and hydrogen generation. However, despite mechanistic insights into *NHx dehydrogenation and OH−-mediated proton-coupled electron transfer, conventional metal catalysts, including Pt and Pt-Ir alloys, still suffer from sluggish kinetics and poor stability. Here, we report that controlling oxygenated co-adsorbates steers the adsorbate-evolution pathway of the eAOR to N2. An exsolved Pt3Ni alloy on a perovskite scaffold selectively stabilizes *OOH and strengthens *NH2 binding via interfacial charge redistribution (elevated surface potential) and a raised Pt d-band center. In situ Fourier transform infrared spectroscopy combined with density functional theory reveals that both the *NHx-to-*N dehydrogenation and *OOH formation steps critically affect the rate-determining process via the N2H4 pathway of the Gerischer–Maurer (G–M) mechanism. Benefiting from (oxy)hydroxide-assisted eAOR, the catalyst delivers mass activity up to 862 A gPt−1, surpassing the state-of-the-art benchmarks. When deployed in a solar-driven ammonia electrolyzer, the catalyst achieves 13.7 mA at cell voltage of 1.0 V, and stable solar-driven hydrogen production at 394 L kWh−1 (NH3 removal rate of 62 mg/day) in landfill leachate-like wastewater conditions. These findings establish an absorbate-assisted mechanism design approach for developing advanced N-species electrocatalysis.
Citation
J. Kim, Y. Hang, H. Park, L. Cheng, M. Gong, A.H. Shah, H. Shin, C. Ye, D.H. Kim, Y. Bu, "Driving Adsorbate Evolution via Oxygenated Surface Species Modulation for Ammonia Electrooxidation," Angewandte Chemie International Edition, vol. 65, no. 4, pp. e23481-e23481, 2025, https://doi.org/10.1002/anie.202523481.
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Angewandte Chemie International Edition
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Keywords
34 Chemical Sciences, 3406 Physical Chemistry, 7 Affordable and Clean Energy
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Wiley