Anderson Localization in 2D Amorphous MoO_3‐x Monolayers for Electrochemical Ammonia Synthesis

Abstract

Two‐dimensional amorphous semiconductor (2DAS) monolayers can be regarded as a new phase of 2D monolayers materials and will serve as a promising field for the various electronic and optoelectronic applications. Here, together with the first‐principles calculations within density functional theory, we experimentally demonstrate that the 2DAS MoO3‐x monolayers can enhance the electrochemical nitrogen reduction reaction (NRR). To be specific, the NH3 yield and faradaic efficiency (FE) reach 35.83 ug h−1 mg−1cat at −0.40 V and 12.01 % at −0.20 V vs. reversible hydrogen electrode (RHE), respectively, and which can be dramatically improved than that of reported defective MoO3 nanosheets. Further theoretical calculations reveal that the high electrochemical performance in NH3 yield is contributed to the strong Anderson localization and electron confinement dimensionally. And such Anderson tail states can resonate effectively with the states of intermediate HNNH, playing the critical role in the rate limiting step of NRR. Integrated experimental findings and theoretical understanding, a new concept of Anderson confinement catalysis is put forward, and could be extended to other 2DAS for potential catalytic reactions.

Self-standing Fe3O4 decorated paper electrode as a binder-free trifunctional electrode for electrochemical ammonia synthesis and Zn–O2 batteries

“…In this study, NH 3 was selectively formed as a product without any traces of N 2 H 4 when quantified by the Watt Chrisp method. 60 was in agreement with that obtained from using the Indophenol blue method (Fig. S12 and Table S3, ESI †), which showed that there was a reliable NH 3 yield rate.…”

“…In this study, NH 3 was selectively formed as a product without any traces of N 2 H 4 when quantified by the Watt Chrisp method. 60 Fig. 2b displays the overall NH 3 production yield rates and subsequent faradaic efficiencies at different applied potentials.…”

Manipulation on Two-Dimensional Amorphous Nanomaterials for Enhanced Electrochemical Energy Storage and Conversion

“…For electrochemical reduction reactions, the optimization of geometric configuration is also recommendable. As typical cases, amorphous MoO 3-x monolayers with oxygen vacancies and amorphous MoS 3 nanosheets with sulfur vacancies can work as efficient NRR catalysts [95,96]. The vacancy defects are able to modulate electron state of catalysts and reduce energetics barriers for facilitating NRR process and simultaneously suppressing HER (Figure 7d).…”

Atomic Modulation, Structural Design, and Systematic Optimization for Efficient Electrochemical Nitrogen Reduction

“…It has been suggested that oxygen vacancies in transition metal oxides enhance N 2 adsorption, activation, and/or stabilization of reaction intermediates such as *NNH, thus promoting NRR activity . The formation of oxygen vacancies signifies exposure of coordinately unsaturated metal sites (i.e., Ti and Mo sites) for the adsorption of N 2 . Additionally, oxygen vacancies can further tune the spin states and magnetic moment of the metal toward formation of more favorable active sites, or trap electrons in a metastable state, favoring further injection into the antibonding orbital of adsorbed N 2 for weakening the NN triple bond toward activation .…”