One-Pot Synthesis of Two-Linker Mixed Al-Based Metal–Organic Frameworks for Modulated Water Vapor Adsorption
Bingqiong Tan, Yanshu Luo, Xianghui Liang, Shuangfeng Wang, Xuenong Gao, Zhengguo Zhang, Yutang Fang
Abstract
Metal–organic frameworks (MOFs) as adsorbents have attracted interest in water-based adsorption applications due to their typical S-shape vapor adsorption isotherms and low regeneration temperature compared to traditionally used materials such as zeolites and silica gel. In this research, the mixed Al-based MOFs (CAU-10-H and Al-fumarate) with isophthalic acid and fumaric acid two ligands were fabricated by one-pot solvothermal method, which displayed a controllable water uptake step. The linker content included in mixed MOFs was assessed by 1H NMR spectroscopy, and the amount of each MOF crystal was uncovered by X-ray diffraction. Nitrogen physisorption data revealed that the BET surface area and pore size distribution of the mixed materials could be modulated between the limits of pure CAU-10-H and Al-fumarate. The dynamic adsorption displayed that their water adsorption isotherms could be tuned in the range of P/P0 = 14–30%. With the increase of the isophthalic acid molar fraction, the water vapor adsorption isotherms of the obtained adsorbents shifted to lower P/P0 values. The desorption performance of the mixed MOFs was between two pure MOFs. Using a one-pot synthetic approach, significant alterations in MOF water adsorption/desorption properties may be realized to accommodate the desired adsorption applications.