Critical Roles of Chalcogenide Anion on Strengthening Stability of Ni₂Mo₆Te₈ for Almost Exclusive Electrocatalysts Nitrate to Ammonia Conversion

Journal Article · 23 December 2023 · Advanced Functional Materials

DOI: https://doi.org/10.1002/adfm.202312079 · OSTI ID:2263299

Xia, Fan ^[1]; Li, Bomin ^[2]; Liu, Yiqi ^[3]; Tan, Haiyan ^[4]; An, Bowen ^[5]; Gao, Siyuan ^[2]; Marks, Tobin J. ^[3]; Cheng, Yingwen  ^[6]

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1. Univ. of Tennessee, Knoxville, TN (United States); Northern Illinois Univ., DeKalb, IL (United States); Northern Illinois University
2. Northern Illinois Univ., DeKalb, IL (United States)
3. Northwestern Univ., Evanston, IL (United States)
4. Univ. of Connecticut, Storrs, CT (United States)
5. Univ. of Tennessee, Knoxville, TN (United States)
6. Univ. of Tennessee, Knoxville, TN (United States); Northern Illinois Univ., DeKalb, IL (United States)

Electrochemical hydrogenation of nitrate to ammonia using renewable electricity is a promising route for sustainability but lacks catalysts that can deliver balanced selectivity, activity, and durability. For this work, a new family of noble metal-free and high-performing Chevrel phase Ni₂Mo₆T₈ (T = S, Se, and Te) catalysts that have similar structural and textural properties and differ presumably only in chalcogenide anion is systematically studied. The side-by-side comparisons allow the uncovering of the critical roles of chalcogenide anions in impacting kinetic activities and long-term durability. The incorporation of anions with larger size and smaller electronegativity from sulfide to selenide and telluride invokes stronger inhibition of the otherwise competing hydrogen evolution reaction (HER) and steers the hydrogenation toward the selective formation of ammonia, thus improving both Faradic selectivity and the turnover frequency to high levels of 99.4% and 21.5 s^–1, respectively, on the Ni₂Mo₆Te₈ catalyst. More significantly, the bulkier anion in the Ni₂Mo₆T₈ catalyst kinetically inhibited the intercalation of electrolyte cations, a major degradation mechanism in the catalyst family examined here and delivered several times improved durability. Therefore, this study introduces novel active motifs for selective nitrate reduction and provides insights into the catalyst degradation mechanism and practical ways to improve durability.

• Research Organization: Northern Illinois Univ., DeKalb, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES). Scientific User Facilities (SUF)
• Grant/Contract Number: SC0023266; AC02-06CH11357; FG02-03ER15457; SC0024448
• OSTI ID: 2263299
• Alternate ID(s): OSTI ID: 2263256
• Journal Information: Advanced Functional Materials, Journal Name: Advanced Functional Materials Journal Issue: 14 Vol. 34; ISSN 1616-301X
• Publisher: WileyCopyright Statement
• Country of Publication: United States
• Language: English