• • HUSY-0.5M catalyst achieves 80.4% phenol conversion and 99.6% alkylation product selectivity, outperforming other zeolites and modified variants; this high selectivity minimizes byproduct formation, crucial for cost-effective fuel precursor production.
• • Citric acid modification preserves HUSY crystallinity while optimizing acid site distribution; HUSY-0.5M exhibits the highest medium-strong acid to total acid ratio, directly correlating with enhanced catalytic activity and stability.
• • Among tested zeolites (MCM-41, Hβ, HUSY, HZSM-5), HUSY shows superior performance due to balanced acidity and larger pore size, enabling efficient diffusion of bulky reactants and products, a key factor for industrial scalability.
• • HUSY-0.5M demonstrates broad applicability across lignin-derived phenolics (p-cresol, anisole, guaiacol), indicating its potential as a versatile catalyst for upgrading diverse bio-oil fractions into high-density aviation fuel precursors.