Preparation of MIL-68(Al) embedded in SBA-15 functionalized with carboxyl groups as a catalyst for 4-nitrophenol to 4-aminophenol

Vinyl-functionalized SBA-15 was synthesised using a one-pot co-condensation method followed by carboxylation via nitric acid, with the intermediate product named SBA-15C. MIL-68 was then synthesised in-situ by adsorption of Al 3 + ions via carboxylate groups on SBA-15C to give the composite xMIL-68(Al)@SBA-15C. A series of characterizations were conducted by Fourier transform infrared spectroscopy, Brunner-Emmet-Teller measurements, X-ray diffraction, X-ray photoelectron spectroscopy, Scanning electron microscope, and Transmission Electron Microscope. xMIL-68(Al)@SBA-15C maintained robust catalytic performance in the NaBH 4 -mediated reduction of 4-nitrophenol to 4-aminophenol, with no significant decrease in activity after five cycles of reuse.