Metasequoia‐like Nanocrystal of Iron‐Doped Copper for Efficient Electrocatalytic Nitrate Reduction into Ammonia in Neutral Media

It is of significance to design catalysts for achieving high-performance electrochemical nitrate reduction to ammonia (NRA) in mild neutral media. However, the faradaic efficiency and selectivity are still far from satisfactory. Here, the fabrication of an efficient catalyst was achieved by rationally doping Fe to Cu into a metasequoia-like nanocrystal of CuFe for NRA in neutral media. Fe doping was found to deepen energy level of the Cu 3d band, favorably tuning adsorption energies of reaction intermediates to promote the NRA. At an applied potential of −0.7 V vs. the reversible hydrogen electrode, the CuFe with approximately 2 % Fe doping content delivered a catalytic current density of 55.6 mA cm−2, which was 2.1 times that of the Cu material. The CuFe also exhibited a faradaic efficiency up to 94.5 %, and a good selectivity of 86.8 %.