Engineered V2O5-supported silicomolybdic acid catalysts for butyl butyrate synthesis: kinetic, mechanistic, and thermodynamic insights toward sustainable aviation fuels
摘要
Sustainable aviation fuels (SAFs) have garnered considerable attention worldwide as a renewable alternative to conventional jet fuels due to growing environmental concerns and the urgent need to reduce carbon emissions. This study investigates microwave-assisted esterification for butyl butyrate synthesis, a promising SAF precursor, using silicomolybdic acid-supported on V2O5 (SMA/V2O5) catalysts. The catalysts were synthesized by wet impregnation with varying silicomolybdic acid content (0-40 wt.%) and characterized using multiple techniques. Optimization of the reaction conditions, including calcination temperature, catalyst loading, stirring speed, reaction time, and temperature, led to the identification of the 30 wt.% silicomolybdic acid-supported V2O5 (SMA/V2O5 30-4) as the most effective catalyst, achieving butyric acid conversion up to 95% and butyl butyrate yield 92%. Kinetic analysis revealed pseudo-first-order behavior following the Eley-Rideal mechanism. Thermodynamic parameters, including activation energy (85.77 kJ·mol-1), Gibbs free energy (ΔG* = 103.80 kJ·mol-1), enthalpy (ΔH* = 82.68 kJ·mol-1), and entropy (ΔS* = -55.12 J·mol-1·K-1), were derived from Arrhenius and Eyring plots. The catalyst maintained high activity across five reaction cycles without substantial deactivation. These results confirm the effectiveness of V2O5-supported silicomolybdic acid catalysts in sustainable butyl butyrate production, with potential applications in SAF synthesis.