Boron-iron nanochains for selective electrocatalytic reduction of nitrate

The electrocatalysis of nitrate reduction reaction (NRR) has been considered to be a promising nitrate removal technology. Developing a highly effective iron-based electrocatalyst is an essential challenge for NRR. Herein, boron-iron nanochains (B-Fe NCs) as efficient NRR catalysts were prepared via a facile low-cost and scalable method. The Fe/B ratio of the B-Fe NCs-x can be elaborately adjusted to optimize the NRR catalytic performance. Due to the electron transfer from boron to metal, the metal-metal bonds are weakened and the electron density near the metal atom centers are rearranged, which are favor of the conversion from NO3 into N-2. Moreover, the well-crosslinked chain-like architectures benefit the mass/electron transport to boost the exposure of abundant catalytic active sites. Laboratory experiments demonstrated that the optimized B-Fe NCs catalyst exhibits superior intrinsic electrocatalytic NRR activity of high nitrate conversion (similar to 80%), ultrahigh nitrogen selectivity (similar to 99%) and excellent long-term reactivity in the mixed electrolyte system (0.02 mol/L NaCl and 0.02 mol/L Na2SO4 mixed electrolyte), and the electrocatalytic activity of the material shows poor performance at low chloride ion concentration (Nitrate conversion of similar to 61% and nitrogen selectivity of similar to 57% in 0.005 mol/L NaCl and 0.035 mol/L Na2SO4 mixed electrolyte). This study provides a broad application prospect for further exploring the high-efficiency and low-cost iron-based functional nanostructures for electrocatalytic nitrate reduction. (C) 2021 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.

Automated summary

Boron-iron nanochains (B-Fe NCs) serve as efficient catalysts for nitrate reduction reaction (NRR) with unique advantages in optimizing NRR catalytic performance, showing promising potential for broad applications.