Electrocatalytic Reduction of NO₃^– to Ultrapure Ammonia on {200} Facet Dominant Cu Nanodendrites with High Conversion Faradaic Efficiency

Abstract

Nitrate (NO3 –) reduction reaction (NtRR) is considered as a green alternative method for the conventional method of NH3 synthesis (Haber–Bosch process), which is known as a high energy consuming and large CO2 emitting process. Herein, the copper nanodendrites (Cu NDs) grown along with the {200} facet as an efficient NtRR catalyst have been successfully fabricated and investigated. It exhibited high Faradaic efficiency of 97% at low potential (−0.3 V vs RHE). Furthermore, the 15NO3 – isotope labeling method was utilized to confirm the formation of NH3. Both experimental and theoretical studies showed that NtRR on the Cu metal nanostructure is a facet dependent process. Dissociation of NO bonding is supposed to be the rate-determining step as NtRR is a spontaneously reductive and protonation process for all the different facets of Cu. Density functional theory (DFT) calculations revealed that Cu{200} and Cu{220} offer lower activation energy for dissociation of NO compared to that of Cu{111}.

Fe Foam-Supported FeS2–MoS2 Electrocatalyst for N2 Reduction under Ambient Conditions

“…The NH 3 yield of FeS 2 −MoS 2 @IF x (x = 100, 300, and 400), MoS 2 , and FeS 2 @IF is approximatively 2.9, 4.2, 2.5, 1.4, and 3.4 × 10 −10 mol s −1 cm −2 , which is suggesting that FeS 2 −MoS 2 @IF 200 (7.1×10 −10 mol s −1 cm −2 ) is highly active for the NRR, further highlighting the important role of the two-phase rational interface engineering and relatively large SSA for NRR activity (Figure 6f). The electrochemical active surface area (ECSA) can further explain the enhanced NRR activity 57 (Figures 7a and S19). The CV curve was measured in the region from 150 to 250 mV ) production of standard and experimental is exhibited in the 1 H NMR (Figure 8b).…”

“…The electrochemical active surface area (ECSA) can further explain the enhanced NRR activity (Figures a and S19). The CV curve was measured in the region from 150 to 250 mV at the rates varying from 10 to 100 mV s –1 .…”

Electrochemical reactions towards the formation of heteroatomic bonds beyond CO2 and N2 reduction

“…[19][20][21] Currently, NH 3 is produced by Haber-Bosch process, which involves inhaling of 400-500 C and 150-200 atm and exhaling CO 2 1.5 times NH 3 . 22 Understanding the requirement of extreme reaction conditions, high energy consumption and its adverse effects on the environment, the NRR is considered as a green and sustainable alternative. 23 Presently, CO 2 and N 2 reduction are largely focused on yielding simple or single products such as C1 compounds and NH 3 , respectively.…”

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.…”

“…[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. 44,52 The nitrate can also be turned into recyclable and valuable ammonia through renewable electricity inputs such as solar or wind sources.…”