Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Rue de l'Industrie 17, CH-1951 Sion, Switzerland.
College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
J Am Chem Soc. 2020 Aug 5;142(31):13415-13425. doi: 10.1021/jacs.0c02371. Epub 2020 Jul 28.
Metal-organic frameworks (MOFs) offer great promise in a variety of gas- and liquid-phase separations. However, the excellent performance on the lab scale hardly translates into pilot- or industrial-scale applications due to the microcrystalline nature of MOFs. Therefore, the structuring of MOFs into pellets or beads is a highly solicited and timely requirement. In this work, a general structuring method is developed for preparing MOF-polymer composite beads based on an easy polymerization strategy. This method adopts biocompatible, biodegradable poly(acrylic acid) (PAA) and sodium alginate monomers, which are cross-linked using Ca ions. Also, the preparation procedure employs water and hence is nontoxic. Moreover, the universal method has been applied to 12 different structurally diverse MOFs and three MOF-based composites. To validate the applicability of the structuring method, beads consisting of a MOF composite, namely Fe-BTC/PDA, were subsequently employed for the extraction of Pb and Pd ions from real-world water samples. For example, we find that just 1 g of Fe-BTC/PDA beads is able to decontaminate >10 L of freshwater containing highly toxic lead (Pb) concentrations of 600 ppb while under continuous flow. Moreover, the beads offer one of the highest Pd capacities to date, 498 mg of Pd per gram of composite bead. Furthermore, large quantities of Pd, 7.8 wt %, can be readily concentrated inside the bead while under continuous flow, and this value can be readily increased with regenerative cycling.
金属-有机骨架（MOFs）在各种气-液相分离中具有很大的应用前景。然而，由于 MOFs 的微晶性质，其在实验室规模上的优异性能几乎无法转化为中试或工业规模的应用。因此，将 MOFs 结构化成为颗粒或珠粒是一个高度需求和及时的要求。在这项工作中，开发了一种基于简单聚合策略制备 MOF-聚合物复合珠粒的通用结构化方法。该方法采用生物相容性、可生物降解的聚（丙烯酸）（PAA）和海藻酸钠单体，这些单体通过 Ca 离子交联。此外，制备过程采用水，因此是无毒的。此外，该通用方法已应用于 12 种不同结构的 MOF 和 3 种 MOF 基复合材料。为了验证结构化方法的适用性，随后使用由 MOF 复合材料 Fe-BTC/PDA 组成的珠粒来从实际水样中萃取 Pb 和 Pd 离子。例如，我们发现仅 1 g 的 Fe-BTC/PDA 珠粒就能够净化 >10 L 含有高毒性 Pb（Pb）浓度为 600 ppb 的淡水，而在连续流动下进行。此外，该珠粒提供了迄今为止最高的 Pd 容量之一，每克复合珠粒可容纳 498 mg 的 Pd。此外，在连续流动下，可以很容易地将大量 Pd（7.8wt%）浓缩在珠粒内部，并且可以通过再生循环很容易地增加其浓度。
