Dealumination of Halloysite Nanotubes as a Method for Enhancing Support Acidity in Ru-Based Catalysts for Guaiacol Hydrodeoxygenation

This study investigates the effects of dealumination time on the textural, structural, and acidic properties of halloysite. Treatment of halloysite with a 1 M sulfuric acid solution for 12 h increased the nanotube lumen diameter (to 24.7 nm), the specific surface area (to 154 m2/g), and the acidity (to 0.312 mmol/g). A series of Ru-based catalysts were synthesized using both pristine and dealuminated halloysites via microwave-assisted incipient wetness impregnation. The catalyst synthesized from dealuminated halloysite exhibited higher specific activity (TOF = 337 h–1), more than twofold higher cyclohexane selectivity, and a higher degree of deoxygenation (49%) compared to its pristine-support counterpart.