Water-tolerant phosphotungstic acid catalyst for controllable synthesis of high-performance biojet fuel

Synthesizing high-performance jet fuels from lignocellulose-derived ketones through aldol condensation is significant for expanding the sources of jet fuel and promoting high-value conversion of biomass. The main problem in aldol condensation is that water generated in such a reaction will decrease the activity of the acid catalyst. Herein, we developed a highly stable, efficient, and water-tolerant SBA-16 confined phosphotungstic acid (HPW) catalyst and applied it to controllably catalyze cross-condensation of cyclopentanone and cyclohexanone. The surface of SBA-16 was modified by alkylimidazole, which creates a relatively hydrophobic environment and anchor points for HPW, leading to resistance to HPW leaching and maintenance of a stable performance for the catalyst. After hydrodeoxygenation, a high-performance fuel blend with a density of approximately 0.905 g/mL and a freezing point lower than −50 °C was obtained. This study provides a general method for preparing highly efficient and stable catalysts for reactions affected by water.