Recent progress of inorganic metal-based catalysts in electrocatalytic synthesis of ammonia

Defect and interface engineering in metal sulfide catalysts for the electrocatalytic nitrogen reduction reaction: a review

“…Besides NH 3 yield, faradaic efficiency (FE) plays an almost equally important role in assessing the performance of a NRR electrocatalyst. 62,63 Due to the competitive HER and by-product of N 2 H 4 , a higher FE means more efficient utilization of electricity and higher NRR selectivity. Faradaic efficiency can be derived from FE = nFCV /( MQ ), where n = 3 is the number of electrons required to produce an NH 3 molecule, F = 96 485 C mol −1 is the Faraday constant, M = 17 is the molecular mass of NH 3 and Q is the total charge during the reaction process.…”

A phosphorus-doped potassium peroxyniobate electrocatalyst with enriched oxygen vacancies boosts electrocatalytic nitrogen reduction to ammonia

“…As one of the typical d-TMs, niobium (Nb) is located at the top of volcanic map for NRR, which may drive the NRR to form NH 3 through association mechanism. 26 The d orbital of Nb has four single electrons and one vacant orbital, endowing the niobium element with polyvalent states from zero to +3 and +5, which has great potential for NRR applications. 12,26 For example, Sun et al reported that Nb 2 O 5 nanofibers are capable of realizing a NH 3 yield rate of 43.6 μg h −1 mg cat −1 at −0.55 V RHE with a FE of 9.26% in 0.1 M HCl.…”

“…26 The d orbital of Nb has four single electrons and one vacant orbital, endowing the niobium element with polyvalent states from zero to +3 and +5, which has great potential for NRR applications. 12,26 For example, Sun et al reported that Nb 2 O 5 nanofibers are capable of realizing a NH 3 yield rate of 43.6 μg h −1 mg cat −1 at −0.55 V RHE with a FE of 9.26% in 0.1 M HCl. 27 Zheng et al demonstrated that NbO 2 nanoparticles achieved a NH 3 production rate of 11.6 μg h −1 mg cat −1 at 0.65 V RHE and presented a peak FE of 32% at 0.60 V RHE .…”

“…As one of the typical d-TMs, niobium (Nb) is located at the top of volcanic map for NRR, which may drive the NRR to form NH 3 through association mechanism. 26 The d orbital of Nb has four single electrons and one vacant orbital, endowing the niobium element with polyvalent states from zero to +3 and +5, which has great potential for NRR applications. 28 Nonetheless, the potential application of Nb-based NRR electrocatalysts is still affected by the competing hydrogen evolution reaction (HER) and the resulting low faradaic efficiency.…”

Fe‐VS2 Electrocatalyst with Organic Matrix‐Mediated Electron Transfer for Highly Efficient Nitrogen Fixation

“…were reported to exhibit NRR performance, [17] especially the transition metal sulfides, [12] which benefited from the following merits. On one hand, the d‐electron orbit in transition metal is beneficial for the adsorption and activation of N 2 molecules; [18] on the other hand, the S atoms in sulfides are apt to combine with Li in Li + electrolyte [6a] to inhibit the HER [19] . Although lithium‐mediated nonaqueous electrolytes show excellent ammonia production activity, it is still limited by the vague mechanism of N 2 reduction process as well as the uneconomic issues and environmental pollution [20] .…”