Unlocking the Molecular-Level Solvent Effect on Cellulose Hydrolysis to Levulinic Acid.

Biorefining cellulose, a major constituent of agricultural residue cell walls, into high-value chemicals improves agriculture's economic and environmental performance. Solvents play a crucial role in determining the selectivity and yield of cellulose hydrolysis products, yet the underlying mechanism of this control remains elusive. This study integrates calculational chemistry and experimental data to elucidate at the molecular level the specific roles of solvent molecules in cellulose hydrolysis. In the composite solvent γ-valerolactone/water, a cellulose conversion of 95.0% and a levulinic acid yield of 65.8% were achieved. Under kinetic control, water molecules both promote catalytically active species generation and, through intermolecular interactions, facilitate their reactive binding with glucose intermediates. GVL solvent molecules stabilize catalytically active species and product molecules via confinement enrichment and electronic structure regulation. This work reveals the decisive role of solvent effects in sustainable biorefining, paving the way for dramatically boosting the agricultural residue utilization efficiency.