Catalytic upgrading of renewable biomass to anti-knock quality fuel additives over mesoporous WO3/FePO4 catalyst: Optimization process parameter and kinetics

Abstract

The esterification of 4-oxopentanoic acid (OP) to amyl-4-oxovalerate (AV) is a green, efficient, and cost-effective process. However, traditional methods for catalyst selection and optimization are inefficient and costly, failing to meet the evolving demands of the fuel industry. In this study, we synthesized a WO₃/FePO₄ (0.3:1 mass ratio) catalyst for the esterification of OP with amyl alcohol (AA) via facile hydrothermal and wet impregnation methods and characterized it with various physio-chemical techniques. The WO₃/FePO₄ catalyst, having larger total acidic sites (1.5 mmol/g), moderate surface area (72 m²/g), void size (3.4 nm), and spherical morphology, exhibited superior catalytic performance, achieving a 92 % OP conversion and 100 % AV selectivity, compared to the FePO₄ catalyst at 100 °C in 3 h with a catalyst dosage of 50 mg. Moreover, the WO₃/FePO₄ catalyst maintains its activity after six recycling cycles. The esterification of OP with different alcohols was also explored. Reaction parameter impacts were examined, and pseudo first-order kinetics revealed that activation energy of 12.65 kJ/mol.