Built‐in Electric Field Triggered Interfacial Accumulation Effect for Efficient Nitrate Removal at Ultra‐Low Concentration and Electroreduction to Ammonia

Abstract

Ab uilt-in electric field in electrocatalyst can significantly accumulate higher concentration of NO 3 À ions near electrocatalyst surface region, thus facilitating mass transfer for efficient nitrate removal at ultra-lowconcentration and electroreduction reaction (NO 3 RR). Am odel electrocatalyst is created by stacking CuCl (111) and rutile TiO 2 (110) layers together,i nw hich ab uilt-in electric field induced from the electron transfer from TiO 2 to CuCl (CuCl_BEF) is successfully formed .T his built-in electric field effectively triggers interfacial accumulation of NO 3 À ions around the electrocatalyst. The electric field also raises the energy of key reaction intermediate *NO to lower the energy barrier of the rate determining step.ANH 3 product selectivity of 98.6 %, alow NO 2 À production of < 0.6 %, and mass-specific ammonia production rate of 64.4 h À1 is achieved, whicha re all the best among studies reported at 100 mg L À1 of nitrate concentration to date.

Electrosynthesis of formamide from methanol and ammonia under ambient conditions

“…C=N in H 2 C=NH is traced based on online DEMS (Supplementary Fig. 24 ) 38 . Accompanied by the on/off switching circuit (Supplementary Fig.…”

Electroreduction of NO3−on tubular porous Ti electrodes

“…37,38 A low concentration of nitrate close to the electrode surface results in preferential hydrogen production, and clearly high mass transport rates are required to improve process efficiency. Specific catalyst design, 39 reactor design, 40 increasing the NO 3 − concentration, 29 or inducing efficient convection in the cell have been investigated to mitigate mass transfer limitations. Herein, we report the use of Ti based hollow fiber electrodes for electrochemical nitrate reduction in acidic electrolyte, which were shown to enable efficient supply of reactant in aqueous solutions to the electrode surface when introducing inert, or reactant containing gas flow.…”

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

“…Generally, the NO 3 RR to ammonia is more favorable than the NRR to ammonia due to the lower dissociation energy of the NO bond (204 kJ mol −1 ) than that of the NN bond (941 kJ mol −1 ), as well as the higher solubility of nitrate in aqueous solution as compared to nitrogen gas. [31][32][33][34][35][36][37][38][39][40][41][42][43] The replacement of ion exchange, reverse osmosis, or bacterial denitrification with the electrochemical NO 3 RR to ammonia is one of the most promising strategies to tackle nitrate degradation. [40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55] This methodology is based on the transformation of nitrate into ammonia that can be more easily recovered from its aqueous solution through regeneration of resins and converted into fertilizer.…”

“…Nonetheless, the present electrocatalytic performance of the NO 3 RR still suffers from a low ammonia yield rate at low at nitrate concentrations (<100 mg L −1 ) due to the mass transfer. 31,32,35,39 On the other hand, the electrochemical NO 3 RR involves complicated nine-proton and eight-electron transfer processes. 32 Numerous intermediates, such as toxic nitrous oxide, hydroxylamine, and diamine, may leak as byproducts.…”