Laboratory of Environmental Systems, National Laboratory Astana, Nazarbayev University, Astana, 010000, Kazakhstan.
Laboratory of Environmental Systems, National Laboratory Astana, Nazarbayev University, Astana, 010000, Kazakhstan; Civil and Environmental Engineering, School of Engineering and Digital Sciences, Nazarbayev University, Astana, 010000, Kazakhstan.
Chemosphere. 2024 Jun;358:142161. doi: 10.1016/j.chemosphere.2024.142161. Epub 2024 Apr 27.
A metallic catalyst, Cobalt N-doped Carbon (Co@NC), was obtained from Zeolitic-Imidazolate Framework-67 (ZIF-67) for efficient aqueous nitrate (NO) removal. This advanced catalyst indicated remarkable efficiency by generating valuable ammonium (NH/NH) via an environmentally friendly production technique during the nitrate treatment. Among various metals (Cu, Pt, Pd, Sn, Ru, and Ni), 3.6%Pt-Co@NC exhibited an exceptional nitrate removal, demonstrating a complete removal of 60 mg/L NO-N (265 mg/L NO) in 30 min with the fastest removal kinetics (11.4 × 10 min) and 99.5% NH selectivity. The synergistic effect of bimetallic Pt-Co@NC led to 100% aqueous NO removal, outperforming the reactivity by bare ZIF-67 (3.67%). The XPS analysis illustrated Co's promotor role for NO reduction to less oxidized nitrogen species and Pt's hydrogenation role for further reduction to NH. The durability test revealed a slight decrease in NO removal, which started from the third cycle (95%) and slowly proceeded to the sixth cycle (80.2%), while NH selectivity exceeded 82% with no notable Co or Pt leaching throughout seven consecutive cycles. This research shed light on the significance of the impregnated Pt metal and Co exposed on the Co@NC surface for the catalytic nitrate treatment, leading to a sustainable approach for the effective removal of nitrate and economical NH production.
一种金属催化剂，钴掺杂碳（Co@NC），是从沸石咪唑酯骨架-67（ZIF-67）中得到的，用于高效去除水中的硝酸盐（NO）。这种先进的催化剂通过在硝酸盐处理过程中采用环保的生产技术，生成有价值的铵（NH/NH），表现出了显著的效率。在各种金属（Cu、Pt、Pd、Sn、Ru 和 Ni）中，3.6%Pt-Co@NC 表现出了卓越的硝酸盐去除效果，在 30 分钟内完全去除 60 mg/L 的 NO-N（265 mg/L 的 NO），具有最快的去除动力学（11.4×10 min）和 99.5%的 NH 选择性。双金属 Pt-Co@NC 的协同效应导致 100%的水相 NO 去除，比裸露的 ZIF-67（3.67%）的反应性更高。XPS 分析表明，Co 促进了 NO 向较低氧化态氮物种的还原，Pt 促进了进一步还原为 NH。耐久性测试表明，NO 去除率略有下降，从第三次循环（95%）开始，缓慢进行到第六次循环（80.2%），而 NH 选择性超过 82%，在七个连续循环中没有明显的 Co 或 Pt 浸出。这项研究强调了浸渍 Pt 金属和 Co@NC 表面暴露的 Co 在催化硝酸盐处理中的重要性，为有效去除硝酸盐和经济地生产 NH 提供了一种可持续的方法。
