Efficient N2 electroreduction to ammonia in an isopropanol–PBS electrolyte using NiFe2O4in situ grown on nickel foam. (14th March 2023)

• Record Type: Journal Article
• Authors: Chen, Chang; Cui, Min; Wang, Qian; Cui, Penglei; Zhang, Cong; Yang, Qian; Ren, Jujie
• Is Part Of: Energy advances. Volume 2:Number 4(2023)
• Page Start: 547
• Page End: 555
• Publication Date: 2023-03-14
• Subjects: Periodicals; Fuel cells; Electrochemistry; Chemical engineering; Thermoelectricity; 621.31242
• DOI: 10.1039/d2ya00364c
• Languages: English
• ISSNs: 2753-1457

Abstract

Abstract : In situ grown nickel ferrite nanosheets are used as cathode for electro-catalytic N2 reduction. PBS-isopropanol is used as the electrolyte to improve N2 solubility and reduce HER, and higher ammonia production rate and FE are obtained. Abstract : The electrocatalytic nitrogen reduction reaction (ENRR) can produce ammonia under environmental conditions and is considered a sustainable alternative to the traditional Haber–Bosch process. However, the ENRR is limited by the solubility of nitrogen (N2 ) and the hydrogen evolution reaction (HER) of the aqueous solution. It is found that the solubility of N2 in isopropanol at room temperature and pressure is more than ten times higher than that in an aqueous solution. In addition, K + can effectively inhibit the HER. Therefore, we use the two-component electrolyte of isopropanol and phosphate buffer solution (PBS) with potassium salt to weaken the influence of low solubility of N2 in an aqueous solution and the competitive HER. In addition, we have in situ grown NiFe2 O4 nanoarrays on nickel foam (NiFe2 O4 /NF) as the electrocatalyst. Finally, a high ammonia yield (1.1 μg h −1 cm −2 ) is achieved and the faradaic efficiency (FE) exceeds 30% at room temperature and pressure. In the end, a model of N2 adsorption on the active (311) crystal surface of NiFe2 O4 was established by means of density functional theory (DFT) calculations, and the activation energy required for the reaction was calculated, proving that the ENRR reported here was an alternate hydrogenation path.