The Metal-Organic Framework MIL-53(Al) Constructed from Multiple Metal Sources: Alumina, Aluminum Hydroxide, and Boehmite

• Published in: Chemistry : a European journal 2015-04, Vol.21 (18), p.6913-6920
• Main Authors: Li, Zehua, Wu, Yi-nan, Li, Jie, Zhang, Yiming, Zou, Xin, Li, Fengting
• Format: Article
• Language: English
• Subjects: adsorption; Alumina hydrate; aluminum; Aluminum base alloys; Aluminum compounds; Aluminum oxide; Boehmite; Chemistry; Construction; hydrothermal synthesis; Metal-organic frameworks; Metalorganic compounds; Thermal stability
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201406531

Three aluminum compounds, namely alumina, aluminum hydroxide, and boehmite, are probed as the metal sources for the hydrothermal synthesis of a typical metal–organic framework MIL‐53(Al). The process exhibits enhanced synthetic efficiency without the generation of strongly acidic byproducts. The time‐course monitoring of conversion from different aluminum sources into MIL‐53(Al) is achieved by multiple characterization that reveals a similar but differentiated crystallinity, porosity, and morphology relative to typical MIL‐53(Al) prepared from water‐soluble aluminum salts. Moreover, the prepared MIL‐53(Al) constructed with the three insoluble aluminum sources exhibit an improved thermal stability of up to nearly 600 °C and enhanced yields. Alumina and boehmite are more preferable than aluminum hydroxide in terms of product porosity, yield, and reaction time. The adsorption performances of a typical environmental endocrine disruptor, dimethyl phthalate, on the prepared MIL‐53(Al) samples are also investigated. The improved structural stability of MIL‐53(Al) prepared from these alternative aluminum sources enables double‐enhanced adsorption performance (up to 206 mg g−1) relative to the conventionally obtained MIL‐53(Al). From minerals to MOFs: Three aluminum compounds, Al2O3, Al(OH)3, and boehmite, were hydrothermally converted into a typical MOF MIL‐53(Al) (see picture; H2BDC=1,4‐benzenedicarboxylate). The use of these water‐ insoluble metal sources can effectively prevent the generation of corrosive acid byproducts, and the corresponding products exhibit improved thermal stability, water‐vapor resistance, and the capacity to remove environmental pollutants in water.