Constructing Asymmetric Polarization Sites on MoO _x Cluster for Efficient Electrochemical N ₂ Reduction

Abstract Activating distal N atoms of the adsorbed N 2 molecules is an effective strategy to break the strong N≡N bond. Designing the catalyst with a fine structure that can fully interact with the distal N atoms is the challenge. Herein, sub‐2 nm ultrasmall MoO x clusters with Mo‐Pd asymmetric polarization sites are constructed on the carbon support (Pd‐MoO x /C) for efficient electrochemical N 2 fixation. Both experiments and theoretical calculations confirm the introduction of Pd can not only accelerate the electron transfer but also interact with the distal N atoms of the adsorbed N 2 molecules to form Mo‐N‐N‐Pd asymmetric polarization effect, thus boosting the activation of N≡N bond and accelerating the following hydrogenation process. Electrochemical measurements show that the optimized Pd‐MoO x /C yields ammonia with a generation rate of 46.5 µg h −1 mg −1 at ‐1.3 V versus Ag/AgCl, which improves nearly three times than that of the MoO x /C. This novel heterogeneous catalyst has great potential in electrocatalysis and will open up a new sight for catalyst design.