| Autor: |
Wang, Jiayi, Xia, Peng, Lu, Yang, Sheng, Mingyu, Lu, Fei, Wang, Xi, Zhou, Min |
| Zdroj: |
Journal of Materials Chemistry A; 10/28/2024, Vol. 12 Issue 40, p27632-27640, 9p |
| Abstrakt: |
Electrochemical reduction of nitrate (NO3RR) is emerging as an efficient alternative method for decentralized ammonia (NH3) synthesis. However, the selectivity of nitrate reduction towards ammonia suffers from competitive hydrogen evolution owing to its preferred thermodynamics of hydrogen evolution. Generally, the localized electronic structure of active species is crucial for the adsorption of pivotal intermediates, thus altering catalytic efficiency and selectivity. Herein, monodispersed iron atoms were precisely anchored onto ultrathin TiO2 nanosheets (Fe1–TiO2), bringing iron and titanium into close proximity and forming asymmetric Fe–Ti atom pairs. It yielded a maximal NH3 faradaic efficiency of 90.1% and production rate of 2.2 mmol per hour per mg of catalyst (mmol h−1 mg−1), surpassing the performance observed over symmetric Ti–Ti pairs in bare TiO2. Theoretical calculations elucidated the intrinsic charge transfer within the Fe–Ti atom pair, which significantly enhanced the selective adsorption of nitrate rather than hydrogen. Moreover, in situ infrared spectroscopy and theoretical calculations clarified that the delocalized electrons within the Fe–Ti pairs could effectively transfer to the antibonding orbital of nitrate and synergistically promote kinetic N–O activation. Consequently, the asymmetric Fe–Ti pairs within Fe1–TiO2 substantially promoted the optimal catalytic activity for nitrate reduction. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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