High-performance artificial nitrogen fixation at ambient conditions using a metal-free electrocatalyst

作者：Weibin Qiu, Xiaoying Xie, Jian‐Ding Qiu, Wei‐Hai Fang, Ru‐Ping Liang, Xiang Zhong Ren, Xuqiang Ji, Guanwei Cui, Guanwei Cui, Abdullah Mohamed Asiri, Ganglong Cui, Ganglong Cui, Bo Tang, Xuping Sun · 发表于：Nature Communications · 年份：2018 · DOI：10.1038/s41467-018-05758-5 · 被引用次数：769 · 研究领域：Ammonia Synthesis and Nitrogen Reduction、Advanced Photocatalysis Techniques、Hydrogen Storage and Materials

Abstract Conversion of naturally abundant nitrogen to ammonia is a key (bio)chemical process to sustain life and represents a major challenge in chemistry and biology. Electrochemical reduction is emerging as a sustainable strategy for artificial nitrogen fixation at ambient conditions by tackling the hydrogen- and energy-intensive operations of the Haber–Bosch process. However, it is severely challenged by nitrogen activation and requires efficient catalysts for the nitrogen reduction reaction. Here we report that a boron carbide nanosheet acts as a metal-free catalyst for high-performance electrochemical nitrogen-to-ammonia fixation at ambient conditions. The catalyst can achieve a high ammonia yield of 26.57 μg h –1 mg –1 cat. and a fairly high Faradaic efficiency of 15.95% at –0.75 V versus reversible hydrogen electrode, placing it among the most active aqueous-based nitrogen reduction reaction electrocatalysts. Notably, it also shows high electrochemical stability and excellent selectivity. The catalytic mechanism is assessed using density functional theory calculations.