Enhanced hydrolysis of cellulose by magnetic carbon-based solid acid catalysts: Effect of hydrothermal pretreatment on the precursor

The selection and design of biomass-derived carbon precursors played a pivotal role in determining the physicochemical properties and catalytic performance of the catalysts. This study investigated the effect of hydrothermal pretreatment on magnetic carbon-based solid acid catalysts (MCSAs) derived from corn stover, focusing on the structural characteristics, catalytic performance, and recyclability. Torrefaction pretreatment and untreated samples were also investigated for comparison. Hydrothermal pretreatment resulted in catalysts with relatively larger pore diameters (2.86-3.11 nm) and higher pore volumes (0.18-0.19 cm³/g), as well as elevated -SO₃H group concentrations (0.68-0.82 mmol/g). After the sixth cycle, the cellulose conversion of HC-210 remained 76.25 %, which maintained 90.23 % of the initial catalytic activity. The findings suggest that hydrothermal pretreatment significantly enhances the catalytic activity and recyclability of MCSAs.