Hydrolysis of Cellulose into Glucose Using a Novel SiO2@IL-PTA Catalyst

First, rice husk was washed with distilled water, treated with 0.1 M nitric acid, and burned at 800°C to recover silica, leading to the formation of RHACCl and sodium silicate, which served as a heterogeneous catalyst after modification with phosphotungstic acid. Two methods were used for catalyst preparation, with CPTES and sodium silicate dissolved in water, followed by titration with 0.1M hydrogen nitrate for catalyst formation via RHACCl reflux distillation. Various analytical techniques characterized the catalysts, showing surface areas of 366 m²/g for SiO2@IL–PTA and 320 m²/g for SiO2@IL–PTA,-dir. The reverse-distilled catalyst exhibited higher carbon and sulfur content but no functional group changes in infrared spectra. Thermal and morphological analyses revealed no significant alterations, with direct methods yielding a crystallinity-rich catalyst. Cellulose hydrolysis at 110°C produced up to 96% monosaccharides in 1.5 hours. Utilizing SiO2@IL–PTA,dir, 85% of glucose was obtained in four hours, and 80% was further hydrolyzed into other compounds within three hours. In six hours, SiO2@IL–PTA,ref converted 70% of cellulose into glucose. After five hours, RHA and RHACCl degraded less than 25% of cellulose. The catalytic efficiency is attributed to the direct conversion of cellulose to glucose and subsequent in-situ transformation of products.