National Engineering Laboratory for Industrial Wastewater Treatment, East China University of Science and Technology, Shanghai 200237, China.
State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China.
J Am Chem Soc. 2022 Mar 16;144(10):4294-4299. doi: 10.1021/jacs.1c12398. Epub 2022 Feb 4.
Structural regulation of the active centers is often pivotal in controlling the catalytic functions, especially in iron-based oxidation systems. Here, we discovered a significantly altered catalytic oxidation pathway via a simple cation intercalation into a layered iron oxychloride (FeOCl) scaffold. Upon intercalation of FeOCl with potassium iodide (KI), a new stable phase of K-intercalated FeOCl (K-FeOCl) was formed with slided layers, distorted coordination, and formed high-spin Fe(II) species compared to the pristine FeOCl precursor. This structural manipulation steers the catalytic HO activation from a traditional Fenton-like pathway on FeOCl to a nonradical ferryl (Fe(IV)═O) pathway. Consequently, the K-FeOCl catalyst can efficiently remove various organic pollutants with almost 2 orders of magnitude faster reaction kinetics than other Fe-based materials via an oxidative coupling or polymerization pathway. A reaction-filtration coupled process based on K-FeOCl was finally demonstrated and could potentially reduce the energy consumption by almost 50%, holding great promise in sustainable pollutant removal technologies.
活性中心的结构调节在控制催化功能方面通常是至关重要的，特别是在基于铁的氧化体系中。在这里，我们通过将简单的阳离子插入层状铁氧氯化物（FeOCl）支架中，发现了一种明显改变的催化氧化途径。FeOCl 与碘化钾（KI）插层后，形成了一种新的稳定相 K 插层 FeOCl（K-FeOCl），与原始 FeOCl 前体相比，其层状滑动、配位扭曲，并形成了高自旋 Fe(II)物种。这种结构调控将 HO 在 FeOCl 上的催化活化从传统的芬顿样途径转向非自由基过氧（Fe(IV)═O）途径。因此，K-FeOCl 催化剂可以通过氧化偶联或聚合途径有效地去除各种有机污染物，其反应动力学比其他基于 Fe 的材料快约 2 个数量级。最后，基于 K-FeOCl 的反应-过滤耦合工艺得到了证明，该工艺可以将能耗降低近 50%，在可持续的污染物去除技术中具有很大的应用前景。
