Overcoming Gas Mass\nTransfer Limitations Using Gas-Conducting\nElectrodes for Efficient Nitrogen Reduction

Electrocatalytic nitrogen reduction reaction (NRR) is\na very attractive\nstrategy for ammonia synthesis due to its energy savings and sustainability.\nHowever, the ammonia yield and Faraday efficiency of electrocatalytic\nnitrogen reduction have been challenges due to low nitrogen solubility\nand competitive hydrogen evolution reaction (HER) in electrolyte solution.\nHerein, inspired by the asymmetric wetting behavior, i.e., superhydrophobicity/hydrophilicity,\nof floating lotus leaves, we demonstrated a gas-conduction electrode\nwith asymmetric gas wetting behavior on the opposite surface, i.e.,\nJanus-Ni/MoO<sub>2</sub>@NF, for efficient nitrogen reduction. It\ncan provide an abundant three-phase interface (TPI) at interfaces\nof Janus-Ni/MoO<sub>2</sub>@NF in electrolyte solution to enhance\nthe contact among N<sub>2</sub>, electrolyte, and electrode. Ascribed\nto this advantage, the hydrophobic side of the Janus electrode not\nonly can repel water molecules to suppress the HER process but also\ncan increase the concentration of N<sub>2</sub> on the interface microenvironment.\nConsequently, the well-designed gas-conducting electrode breaks gas\nmass transfer limitation. Furthermore, Janus-Ni/MoO<sub>2</sub>@NF\ndelivers a record-high NH<sub>3</sub> yield rate of 5.865 μg·h<sup>–1</sup>·cm<sup>–2</sup> and a Faradaic efficiency\nof 36.14% at an extremely low potential of 0 V vs RHE in 0.1 M Na<sub>2</sub>SO<sub>4</sub> under ambient conditions, which are 22 and\n18 times higher than those of the conventional electrode, respectively.\nTherefore, the gas-conducting electrodes can dramatically improve\nthe activity and selectivity in electrocatalytic NRR. Additionally,\nthe unique interface design provides inspiration for other sustainable\nelectrochemical reactions involving gas electrocatalytic correlation.