Synthesis of Magnetically Modified Copper-Based Metal-Organic Frameworks for Cellulose Hydrolysis

This study was aimed at the synthesis, characterization, and cellulose hydrolysis potential of pristine and magnetically modified Cu-based metal-organic frameworks (MOFs; Cu-BDC and MNPs@Cu-BDC). The MNPs@Cu-BDC was synthesized through an encapsulation approach by coating the presynthesized Fe₃O₄ nanoparticles (MNPs). The materials were characterized using Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis, and Brunauer-Emmett-Teller techniques. The FT-IR analysis confirms the presence of the corresponding functional groups in the synthesized Fe₃O₄, Cu-BDC, and MNPs@Cu-BDC materials. The SEM image depicted that the magnetic MOF had a rough surface with regular octahedral and embedded spherical-shaped particles, unlike pristine Cu-BDC. The XRD pattern of MNPs@Cu-BDC revealed distinctive signals of Fe₃O₄ along with Cu-BDC diffraction patterns. The catalytic activity of the synthesized MNPs@Cu-BDC was analyzed and optimized by varying the catalyst dose (0-5 mg), temperature range (120-200 °C), and residence time (30-120 min). The prepared MOF exhibited high catalytic activity toward carboxyl methylcellulose, and it achieved a total reducing sugar yield of 95.7 mg/g at 160 °C for 120 min. The MNPs@Cu-BDC catalyst was stable enough until 300 °C. Additionally, the catalyst displayed good reusability, maintaining a production rate of 40.81 mg/g after five cycles. Hence, these results underscore the potential of MNPs@Cu-BDC as an effective catalyst for cellulose hydrolysis, with promising recyclability features.