Reaction pathways on N-substituted carbon catalysts during the electrochemical reduction of nitrate to ammonia

Abstract

Electrochemical reduction of nitrate into ammonia is one potential strategy to valorize pollutants needed to close the nitrogen cycle. The understanding of carbonaceous materials as metal-free representatives of electrocatalysts is...

Supramolecular confinement synthesis of ultrafine iron nitride nanocrystals for the oxygen reduction reaction in Zn–air batteries

“…3b) display the distinct D band at 1330 cm −1 corresponding to the defects of carbon and the G band at 1520 cm −1 corresponding to sp 2 -hybridized graphitic carbon. 30 The calculated proportions of the D to G band for Fe 3 N/NC-800 and Fe 3 N/NC-900 are 0.93 and 0.92, respectively. The higher I D / I G ratio of Fe 3 N/NC-800 means more local defects in the carbon substrate, which may anchor the Fe 3 N nanocrystals and prevent them from agglomerating.…”

Structural engineering of catalysts for ammonia electrosynthesis from nitrate: recent advances and challenges

“…[39][40][41] The first step of the NitRR is the adsorption of nitrate on the active sites, which is considered to be the rate-determining step. 42,43 Adsorption energy plays a pivotal role in the initiation of the reaction and the adsorption efficiency is related to the nitrate concentration, cathode materials, and the mass transfer rate of reactants. 44,45 After the absorption step, the electroreduction of NO 3 À ad.…”

“…Moreover, nitrite can be reduced to NO by direct electron transfer and a deoxidation process. 42 This step is a divergent center for generating dinitrogen or ammonia. The selectivity of the subsequent pathway is determined by nitric oxide.…”

Progress and prospects of electrochemical reduction of nitrate to restore the nitrogen cycle

“…148 The nitrogen doped carbon (NDC) material maintains a Faraday efficiency of 73.1% reduction to ammonia over a 48 hour period, making it an attractive choice for this process. 149 The electrochemical reduction of nitrate also exhibits outstanding performance in boron-doped diamond (BDD). 150,151 In the nitrate reduction process, when BDD is employed as both an anode and a cathode simultaneously, the hydroxyl radicals produced by the anode contribute to enhancing the oxidation of NH 3 , which produces nitrogen gaseous substances.…”