Green Synthesis of Acid-Base Bi-functional UiO-66-Type Metal-Organic Frameworks Membranes Supported on Polyurethane Foam for Glucose Conversion

We herein report a green (aqueous solutions), mild (90 °C, atmospheric pressure), and scalable modulated hydrothermal (MHT) synthesis of acid-base bi-functional UiO-66-type metal-organic frameworks membranes supported on polyurethane. Polyurethane foam was first modified with polydopamine (PDA) to obtain versatile carrier, i. e., PU@PDA. Then the novel acid-base bi-functional UiO-66-type MOFs membranes have been prepared on PU@PDA for the first time by in situ MHT method. By simply varying the ratio of organic ligands of monosodium 2-sulfoterephthalate and 2-aminoterephthalic for preparing MOFs membranes, the acidity and basicity of obtained composites, i. e., UiO-66-SO₃H-NH₂/PDA@PU can be easily adjusted. The synthesized materials were well characterized and their catalytic performances were evaluated in one-pot glucose to 5-hydroxymethylfurfural (HMF) conversion. Results revealed the acid-base bi-functional catalyst possessing high activity and excellent stability. This work provides a general and economically viable approach for the large-scale synthesis of water-stable MOFs membranes catalysts with repeatable quality remains the key step for their massive production and commercialization.