Document Type : Original Article

Authors

• Hussein M. Hussein ¹
• Bahaa T. Shawky ²
• Hamed Mohamed Abdel Barry ³
• Ibrahim El Tantawy El Sayed ³

¹ Department of Chemistry, Faculty of Science, Menoufia University, Shebin El Koom 13829, Egypt.

² Microbial Chemistry Department, Biotechnology Research Institute, National Research Centre, Cairo, Egypt.

³ Department of Chemistry, Faculty of Science, Menoufia University, Shebin El Koom - 13829, Egypt.

Abstract

Magnetic iron oxide nanoparticles are a promising support for immobilization of enzymatic and acid catalysts for the hydrolysis of cellulose due to their large surface area, modifiable surface, and easy magnetic separation. Here, Fe₃O₄ nanoparticles were synthesized using coprecipitation yielding quasi-spherical particles of 15.3±2.7 nm diameter, PDI 0.311, and zeta potential -18.7 mV, confirming moderate monodispersity and colloidal stability, and employed as support for cellulase immobilization (biocatalyst) and a core for carbon coating then sulfonation to produce a magnetically separable solid acid (Fe₃O₄@C-SO₃H). Fe₃O₄ nanoparticles were prepared by precipitation from FeCl₃.6H₂O and FeCl₂.4H₂O in a basic solution, tested for basic magnetic, color and dispersion characteristics, and then characterized using spectroscopy and microscopy before being used for the enzyme adsorption and the carbon coating/sulfonation. The immobilized cellulase on Fe₃O₄ nanoparticles was applied to the hydrolysis of carboxymethyl cellulose, while Fe₃O₄@C-SO₃H was applied to the hydrolysis of pretreated cellulose. In all cases, glucose was detected by the glucose oxidase-peroxidase method, and the reusability of the magnetic materials was tested by multiple recycling runs retaining>80% activity after 5 cycles, which demonstrated that they maintained high activity after at least five runs. Response surface methodology optimization revealed peak glucose yields of 84.93% from cellulose at pH 5, 60°C, 2.5% substrate, and 17.05 mg/g catalyst loading (R²=0.9732), approaching 91.6% of commercial enzyme performance (92.7%) with superior pH/temperature stability and recyclability

This study shows that straightforward Fe₃O₄-based materials can be used to prepare magnetically recoverable and reusable catalysts for the conversion of cellulose into fermentable sugars.

Keywords

• Fe₃O₄ nanoparticles
• Magnetic nanocatalysts
• Cellulase immobilization
• Magnetic recyclability
• Solid acid catalyst

Main Subjects

• Applications of Artificial Intelligence Studies in Renewable Energies