Key Laboratory of Mesoscopic Chemistry, State Key Laboratory of Coordination Chemistry, State Key Laboratory of Analytical Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, No.168, Xianlin Road, Nanjing, 210023, China.
Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering, Nanjing University, No.168, Xianlin Road, Nanjing, 210023, China.
Angew Chem Int Ed Engl. 2023 Jul 3;62(27):e202305246. doi: 10.1002/anie.202305246. Epub 2023 May 24.
Nitrate-containing industrial wastewater poses a serious threat to the global food security and public health safety. As compared to the traditional microbial denitrification, electrocatalytic nitrate reduction shows better sustainability with ultrahigh energy efficiency and the production of high-value ammonia (NH ). However, nitrate-containing wastewater from most industrial processes, such as mining, metallurgy, and petrochemical engineering, is generally acidic, which contradicts the typical neutral/alkaline working conditions for both denitrifying bacteria and the state-of-the-art inorganic electrocatalysts, leading to the demand for pre-neutralization and the problematic hydrogen evaluation reaction (HER) competition and catalyst dissolution. Here, we report a series of Fe M (M=Fe, Co, Ni, Zn) trinuclear cluster metal-organic frameworks (MOFs) that enable the highly efficient electrocatalytic nitrate reduction to ammonium under strong acidic conditions with excellent stability. In pH=1 electrolyte, the Fe Co-MOF demonstrates the NH yield rate of 20653.5 μg h mg with 90.55 % NH -Faradaic efficiency (FE), 98.5 % NH -selectivity and up to 75 hr of electrocatalytic stability. Additionally, successful nitrate reduction in high-acidic conditions directly produce the ammonium sulfate as nitrogen fertilizer, avoiding the subsequent aqueous ammonia extraction and preventing the ammonia spillage loss. This series of cluster-based MOF structures provide new insights into the design principles of high-performance nitrate reduction catalysts under environmentally-relevant wastewater conditions.
含硝酸盐的工业废水对全球食品安全和公众健康安全构成严重威胁。与传统的微生物反硝化相比，电催化硝酸盐还原具有超高的能量效率和高价值氨 (NH₃) 的生产，具有更好的可持续性。然而，大多数工业过程（如采矿、冶金和石油化工工程）产生的含硝酸盐废水通常呈酸性，这与反硝化细菌和最先进的无机电催化剂的典型中性/碱性工作条件相矛盾，导致需要进行预中和以及存在析氢反应 (HER) 竞争和催化剂溶解等问题。在这里，我们报告了一系列的 Fe M（M=Fe、Co、Ni、Zn）三核簇金属-有机骨架（MOF），它们能够在强酸性条件下高效电催化硝酸盐还原为铵，具有出色的稳定性。在 pH=1 的电解质中，FeCo-MOF 表现出 20653.5μg h⁻¹ mg⁻¹ 的 NH₃产率，NH₃法拉第效率（FE）为 90.55%，NH₃选择性为 98.5%，电催化稳定性长达 75 小时。此外，在高酸性条件下成功的硝酸盐还原可直接生成作为氮肥的硫酸铵，避免了后续的氨水提取，防止了氨泄漏损失。该系列基于簇的 MOF 结构为在环境相关废水条件下设计高性能硝酸盐还原催化剂提供了新的思路。
