Highly active iron phosphide catalysts for selective electrochemical nitrate reduction to ammonia
The electrochemical reduction reaction of the nitrate ion (NO3−), a widespread water pollutant, to valuable ammonia (NH3) is a promising approach for environmental remediation and green energy conservation. The development of high-performance electrocatalysts to selectively reduce NO3− wastes into value-added NH3 will open up a different route of NO3− treatment, and impose both environmental and economic impacts on sustainable NH3 synthesis. Transition metal phosphides represent one of the most promising earth-abundant catalysts with impressive electrocatalytic activities. Herein, we report for the first time the electrocatalytic reduction of NO3− using different phases of iron phosphide. Particularly, FeP and Fe2P phases were successfully demonstrated as efficient catalysts for NH3 generation. Detection of the in-situ formed product was achieved using electrooxidation of NH3 to nitrogen (N2) on a Pt electrode. The Fe2P catalyst exhibits the highest Faradaic efficiency (96 %) for NH3 generation with a yield (0.25 mmol h−1 cm-−2 or 2.10 mg h−1 cm−2) at − 0.55 V vs. reversible hydrogen electrode (RHE). The recycling tests confirmed that Fe2P and FeP catalysts exhibit excellent stability during the NO3− reduction at − 0.37 V vs. RHE. To get relevant information about the reaction mechanisms and the fundamental origins behind the better performance of Fe2P, density functional theory (DFT) calculations were performed. These results indicate that the Fe2P phase exhibits excellent performance to be deployed as an efficient noble metal-free catalyst for NH3 generation.
2023
2023-02-02 10:31:57
1033
iron phosphide, electrocatalysts, nitrates reduction ammonia, DFT calculations
Takwa
Chouki
70
Manel
Machreki
70
Iwona A.
Rutkowska
70
Beata
Rytelewska
70
Pawel Jozef
Kulesza
70
Georgi
Tyuliev
70
Moussab
Harb
70
Luis Miguel
Azofra
70
Saim
Emin
70
COBISS_ID
3
140447235
UDK
4
54
ISSN pri članku
9
2213-3437
DOI
15
10.1016/j.jece.2023.109275
NUK URN
18
URN:SI:UNG:REP:BRFWNGNK
RAZ_Chouki_Takwa_i2023.pdf
8336492
Predstavitvena datoteka
2023-02-02 12:13:16
0
Izvorni URL
2023-12-18 09:38:08