<![CDATA[The growing demand for sustainable chemical production has intensified interest in biomass-derived platform chemicals. This study investigates the thermal methanolysis of Gmelina arborea leaves, an abundant non-edible lignocellulosic biomass, for the selective production of furfural and 5-methylfurfural (5-MF). Using barium chloride (BaCl2) as a Lewis acid catalyst in methanol medium, the process was conducted under mild conditions (60 oC, atmospheric pressure) across reaction times of 10 - 60 min. GC-MS analysis revealed that furfural yield peaked at 3.91% (143.7 mg/g) after 30 min, while 5-MF reached 2.78% (102.5 mg/g) at 20 min. The distinct temporal profiles highlight the influence of reaction kinetics and thermal sensitivity on product selectivity. Statistical analysis confirmed reaction time significantly affected yields (p < 0.05), and reproducibility assessment showed excellent precision (RSD < 2.13%). Mechanistic insights suggest Ba2+ ions facilitate selective glycosidic bond cleavage in hemicellulose, promoting sugar dehydration to furan derivatives, with methanol suppressing polymerisation side reactions. This work offers a low-energy, acid-moderated route for biomass valorisation, addressing key limitations of conventional methods, corrosive acids, high temperatures (>150 oC), and pressurised systems. The results demonstrate that BaCl2 effectively catalyses solvolytic hydrolysis and dehydration with high selectivity while minimising degradation pathways. This study underscores the potential of Gmelina arborea as a renewable feedstock in green chemical manufacturing and contributes to sustainable biorefinery development by demonstrating an environmentally benign catalytic system for converting underutilised plant residues into valuable platform chemicals, supporting the transition toward a circular bioeconomy.]]>
