Catalytic activity of nZVIx@AC/NF on electroreduction of nitrate to ammonia:Effect of nano-valent iron loading

Nano zero-valent iron (nZVI) has high catalytic activity for nitrate electroreduction, however, it is easy to aggregate due to the nature magnetic properties. Herein we choose coconut activated carbon(AC) as the supporter to disperse the nanoparticles. Coconut AC primarily consists of a large number of micropores and mesopores. The micropores mainly provide large surface area to adsorption the nitrate ions first, and mesopores are responsible for the supporting nZVI particles. The adsorbed nitrate can migrate easily to the nZVI sites for reduction reaction. The aim of this paper is to determine the maximum nZVI loading capacity on AC without agglomeration, and also their corresponding activity for the electroreduction of nitrate to ammonia. The morphology and structural characteristics of the electrodes showed that nZVI can be evenly distributed on AC when the loading lower than 40 wt%, and the highest. NH3Faradic efficiency of 97.2 % was obtained with nZVI40@AC at −7.5 mA/cm2. In addition, to clarify the sensitivity of the operating parameters the nitrated reduction. Response surface area was applied to evaluate the interactive effect between the operating parameters.