Preparation of Magnetic Sulfonated Carbon-Based Solid Acid Catalysts for the Hydrolysis of Cellulose

Magnetic sulfonated carbon. based solid acid catalysts (Fe/C-SO3H) were prepared by the pyrolysis of cellulose and subsequent sulfonation. The catalyst samples were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X. ray diffraction (XRD), X. ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR) spectroscopy, and vibrating sample magnetometry (VSM). Their catalytic properties for the hydrolysis of cellulose were investigated. Results show that Fe exists in the carbon body in the form of gamma-Fe2O3 and the Fe/C-SO3H catalyst has superparamagnetic properties. In the hydrolysis reaction, cellulose conversion reached 40.6% over Fe/C-SO3H under optimal conditions. Furthermore, the catalyst could be steadily dispersed in the reaction mixture and be separated using an externally applied magnetic field. However, the catalytic performance dropped after the first run. The reason for deactivation is deduced to be a reduction in the amount of sulfonic acid groups on the surface of the catalyst.