Unveiling the Synergy of O‐Vacancy and Heterostructure over MoO_3‐x/MXene for N₂ Electroreduction to NH₃

Abstract

The electrochemical N2 reduction reaction (NRR) offers a promising approach for sustainable NH3 production, and modulating the structural/electronic configurations of the catalyst materials with optimized electrocatalytic properties is pivotal for achieving high‐efficiency NRR electrocatalysis. Herein, vacancy and heterostructure engineering are rationally integrated to explore O‐vacancy‐rich MoO3‐x anchored on Ti3C2Tx‐MXene (MoO3‐x/MXene) as a highly active and selective NRR electrocatalyst, achieving an exceptional NRR activity with an NH3 yield of 95.8 µg h−1 mg−1 (−0.4 V) and a Faradaic efficiency of 22.3% (−0.3 V). A combination of in situ spectroscopy, molecular dynamics simulations and density functional theory computations is employed to unveil the synergistic effect of O‐vacancies and heterostructures for the NRR, which demonstrates that O‐vacancies on MoO3‐x serve as the active sites for N2 chemisorption and activation, while the MXene substrate can further regulate the O‐vacancy sites to break the scaling relation to effectively stabilize *N2/*N2H while destabilizing *NH2/*NH3, resulting in more optimized binding affinity of NRR intermediates toward reduced energy barriers and an enhanced NRR activity for MoO3‐x/MXene.

PdFe Single‐Atom Alloy Metallene for N2 Electroreduction

“…[1][2][3][4][5] Diverse groups of materials have been exploited as potential NRR catalysts, [6][7][8] with their performance further promoted by engineering morphology, [9][10][11] introducing defects/dopants, [12][13][14][15] and constructing heterostructures. [16][17][18][19][20][21] Single-atom catalysts (SACs) have stimulated tremendous interest in electrocatalysis owing to their maximum atomic utilization efficiency and strong metal-support interactions. A variety of Fe, [22][23][24] Ru, [25][26][27] Ni, [28] Mo [29] and Cu [30] SACs have been explored for the NRR, where the atomic metal sites are found to be energeti-cally in favor of adsorbing N 2 and dissociating the N�N bond.…”

Ultrasmall iridium nanoparticles on graphene for efficient nitrogen reduction reaction

“…[11][12][13][14][15][16][17][18][19][20][21][22] However, the N 2 electroreduction suffers from intrinsically sluggish kinetics for the N 2 reduction reaction (NRR) due to the high energy for simulating the stable N-N triple bond, complicated multi-electron reactions and competitive hydrogen evolving reaction (HER). [23][24][25][26][27][28] To tackle these limitations, it is urgently demanded to explore highly active and selective NRR electrocatalysts. [29][30][31][32][33][34][35][36][37][38][39][40] Iridium (Ir)-based materials have been recently investigated as promising NRR catalysts owing to their high catalytic activity, fast reaction kinetics, good chemical stability and tunable electronic structure.…”

Confinement catalysis of a single atomic vacancy assisted by aliovalent ion doping enabled efficient NO electroreduction to NH3

“…However, the practical application of the NRR is limited by the low conversion efficiency and NH 3 yield, mainly resulting from the chemically inert properties of N 2 . [1][2][3][4][5][6][7] Very recently, the electrocatalytic NO x (NO, NO 2 À , and NO 3 À ) reduction reaction (NO x RR) to yield NH 3 stood out as an alternative to the NRR, thanks to the much easier activation of the N]O bond (204 kJ mol À1 ) than the N^N bond (941 kJ mol À1 ). [8][9][10] NO emitted from factories, power stations, and motor vehicles is one of the main sources of atmospheric contamination.…”