Energy-Efficient Ammonia Synthesis from Nitrate via CoNi Alloys Incorporated in Carbon Frameworks

作者：Fengcai Lei, Yiming Zhang, Mengmeng Xu, Kun Li, Menghan Zhang, Ruixue Huai, Junfeng Xie, Pin Hao, Guanwei Cui, Bo Tang · 发表于：ACS Sustainable Chemistry & Engineering · 年份：2023 · DOI：10.1021/acssuschemeng.3c01688 · 被引用次数：44 · 研究领域：Ammonia Synthesis and Nitrogen Reduction、Advanced Photocatalysis Techniques、Caching and Content Delivery

As a nitrogen-containing source, nitrate is regarded as a promising precursor for generating ammonia (NH 3 ) through electrochemical processes that can potentially mitigate the problem of groundwater contamination and the hydrogen-carrier energy crisis. Herein, we report a cobalt zeolitic imidazolate framework (ZIF-67)-derived catalyst of CoNi alloys incorporated in N-doped carbon frameworks for nitrate electroreduction. Computational results obtained using the density functional theory give a deep insight that the structure of CoNi alloys embedded in the N-doped carbon skeleton can inhibit the production of hydrogen and facilitate the hydrogenation of *NO intermediates. The enriched active sites from the ZIF-67-derived structure and the introduction of Ni in the catalyst afford desirable electrocatalytic performance. Finally, the optimized CoNi@NC hybrid can achieve an ammonia production of 168 mmol g cat –1 h –1 and a Faradaic efficiency of ∼93% at a potential as low as −0.1 V vs reversible hydrogen electrode (RHE). The highest yield rate of 1254 mmol g cat –1 h –1 can be detected at −0.6 V vs RHE. This study can inspire further development of non-noble metal-based hybrid electrocatalysts for nitrate reduction and also anticipation into sustainable synthesis of carbon-related fuels from CO 2 reduction.