Metal–organic framework-derived Cu nanoparticle binder-free monolithic electrodes with multiple support structures for electrocatalytic nitrate reduction to ammonia

Abstract

The Cu-BTC-Cu effectively overcame the weaknesses of unsatisfactory ammonia yield, enormous amounts of nitrite as a byproduct, and the poor stability of Cu-based catalysts.

Unveiling Cutting‐Edge Developments in Electrocatalytic Nitrate‐to‐Ammonia Conversion

“…In the eNitRR process, Pd (111) has a higher current density, and FE for NH 3 production up to 79.91% at −0.7 V versus RHE, which indicates that Pd (111) has a better nitrate reduction performance. When Pd (111) was used as the catalyst in a Na 2 SO 4 solution containing 0.1 m NO 3 − , the NH 4 + yield rate reached 2.74 mmol h −1 mg cat −1 , which is 1.9 and 1.4 times higher than that obtained with palladium nanocrystals on Pd (100) and Pd (110), respectively. The stability of Pd (111) in eNitRR was demonstrated by its consistent selectivity in terms of NH 4 + yield rate and FE over 10 cycles at −0.7 V versus RHE, showing only slight fluctuations and indicating the robust stability of Pd (111) in eNitRR.…”

“…The stability of Pd (111) in eNitRR was demonstrated by its consistent selectivity in terms of NH 4 + yield rate and FE over 10 cycles at −0.7 V versus RHE, showing only slight fluctuations and indicating the robust stability of Pd (111) in eNitRR. The eNitRR mechanism on Pd (111), Pd (110), and Pd (100) surfaces was calculated by DFT to explain why Pd (111) has high eNitRR performance. as depicted in Figure 6d.…”

Recent Progress and Perspectives on Transition Metal-Based Electrocatalysts for Efficient Nitrate Reduction

“…Therefore, the future direction for improving the electrocatalytic performance of MOF materials is to improve the electrochemical nitrate reduction performance by improving the coordination environment, electronic structure, and support structure of the metal through suitable organic ligands or using bimetallic MOF materials. Wang et al 131 prepared polyhedron-loaded (Cu-BTC-Cu), rod-loaded (Cu-BTEC-Cu), and unloaded (Cu-BDC-Cu) copper nanoparticles for monolithic electrodes, in which Cu-BTC-Cu was found to have high catalytic performance and stability and to inhibit nitrite production, with an NH 3 yield of 4.0 mg h −1 cm −2 and FE of 83.8% at −1.0 V vs RHE.…”

Mixed-valence Cu-based heterostructures for efficient electrochemical nitrate reduction to ammonia

“…2 Copper (Cu) is regarded as one of the most active metals for the NO 3 RR since it exhibits high current density and superior kinetics for the reduction of nitrate to nitrite. 6–12 This is attributed to similar d-orbital energy levels of Cu to the lowest unoccupied molecular π* orbital (LUMO π*) of NO 3 − , thereby facilitating electron transfer. 13 Moreover, Cu-based catalysts, with the characters of low cost, high conductivity, and inferior activity for the competing hydrogen evolution reaction (HER), are ideal candidates for the electrochemical NO 3 RR to ammonia.…”