Designing Amino-Functionalized Metal–Organic Frameworks for Highly Efficient and Selective Separation of Furan Compounds from Water

Furan compounds, such as furfural (Fur) and 5-hydroxymethylfurfural (5-HMF), are significant platform molecules from biomass. They have high boiling points and coexist with raw carbohydrates in aqueous solutions. This makes their efficient adsorption and selective separation a critical challenge in sustainable biorefinery processes. This study focuses on synthesizing amino-functionalized MOFs by grafting amino silanes onto UiO-67 to achieve the efficient adsorption and selective separation of 5-HMF or Fur from aqueous solutions. The optimized adsorbent UiO-67-2AS(10) exhibits a remarkable adsorption capacity for 5-HMF (1530 mg/g) and Fur at room temperature (1267 mg/g). Under optimal conditions, the extraction efficiencies are 12% for 5-HMF and 19% for Fur. Additionally, UiO-67-2AS(10) does not exhibit a clear affinity toward sugars (sucrose, xylose, and fructose) in water, enabling selective separation of furan compounds from reducing sugars. The adsorption process is accurately described by both the Langmuir model and the pseudo-second-order kinetic model. UiO-67-2AS(10) exhibits remarkable adsorption performance due to the π–π interactions and hydrogen bonding interactions with the furan compound.