Anderson Localization in 2D Amorphous MoO3‐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 MoO 3‐ x monolayers can enhance the electrochemical nitrogen reduction reaction (NRR). To be specific, the NH 3 yield and faradaic efficiency (FE) reach 35.83 ug h −1 mg −1 cat 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 MoO 3 nanosheets. Further theoretical calculations reveal that the high electrochemical performance in NH 3 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.