Atomically Dispersed Manganese Lewis Acid Sites Catalyze Electrohydrogenation of Nitrogen to Ammonia

Abstract

Ambient electrochemical nitrogen fixation is a promising and environmentally benign route for producing sustainable ammonia, but has been limited by poor performance of existing catalysts that promote the balanced chemisorption of N 2 and subsequent electrochemical activation and hydrogenation. Herein, we describe the highly selective and efficient electrohydrogenation of nitrogen to ammonia using hollow nanorod-

Emerging Ultrahigh‐Density Single‐Atom Catalysts for Versatile Heterogeneous Catalysis Applications: Redefinition, Recent Progress, and Challenges

“…[ 204 ] However, due to the high stability of N≡N triple bond and the slow adsorption of N 2 , the development of efficient electrocatalytic materials is the bottleneck of electrocatalytic NRR technology at room temperature and pressure. [ 205 ] Atomically dispersed metal catalysts can maximize the use of atoms for catalytic reactions and are also widely used in efficient NRR conversion. [ 206 ] In particular, the single‐atom design strategy by high atom density (or high metal loading) has unique advantages in constructing NRR electrocatalysts with high Faraday efficiency and high NH 3 yield (see Figure and Table 4 for details).…”

Activation of MoS2 monolayer electrocatalysts via reduction and phase control in molten sodium for selective hydrogenation of nitrogen to ammonia

“…The resonance peak at 1110 cm −1 can be assigned to the N–N stretching of adsorbed N 2 H x (1 ≤ x ≤ 4) species, with the peak intensity increasing with increasing reaction time. 40,41 This clearly reflects that the NN triple bond is cleaved into a single bond within the catalyst/electrolyte interface. Notably, extra peaks that increased with the reaction time were observed, located at 1320 and 1465 cm −1 , corresponding to H–N–H bending and –NH 2 wagging, 38 respectively.…”

“…Against with 14 N and Ar feeding gas, the doublet pattern is attributed to 15 NH 4 + in the 1 H NMR spectra. The ratio of the 14 NH 4 + / 15 NH 4 + product is proportional to the initial feeding gas ratio of 14 N 2 / 15 N 2 (1.86 vs 2.00), showing that the product is stemmed from the electrocatalytic N 2 gas reduction rather than the contaminations and/or decomposition of catalysts [37][38][39] . In addition, the nearly linear correlation between the NH 3 concentration and electrolysis duration further demonstrate the MoS 1.59 -H/T is a stable catalyst for electrochemical nitrogen fixation (Figure S11).…”

“…The resultant MoS x -H/T catalysts are deposited on carbon paper working electrodes and employed for the NRR in a three-compartment cell under ambient condition (Figure S5). The NRR performance was evaluated by quantifying the generated NH 3 via the indophenol blue method (Figure S6), and the possible formation of byproduct (N 2 H 4 ) was also quantified by the Watt and Chrisp method 37 . Figure 4a demonstrates the Faradaic efficiencies (FEs) of different MoS x -H/T catalysts at various potentials, of which, the MoS 1.79 -H/T exhibits the highest average NH 3 yield rate and FE of 93.2 μg h -1 mg cat -1 and 20.5% at -0.4…”

“…S6 † ), and the possible formation of byproduct (N 2 H 4 ) was also quantified using the Watt and Chrisp method. 37 Fig. 4a shows the faradaic efficiencies (FEs) of the different MoS x -H/T catalysts at various potentials, of which MoS 1.79 -H/T exhibits the highest average NH 3 yield rate and FE of 93.2 μg h −1 mg cat −1 and 20.5% at −0.4 V vs. RHE, respectively, much higher than that of pristine 2H-MoS 2 (FE: 0.5%) and the other MoS 2 -H/T catalysts (FEs from 3.2 to 11.5%), implying that the 1T phases and SVs mainly promote the electrocatalytic NRR performance.…”