Chitosan-derived porous activated carbon aerogels: Fabrication and catalytic application in biodiesel production

Abstract

This study developed a hierarchically porous carbon aerogel catalyst from chitosan for the conversion of soybean oil to biodiesel. The catalyst was fabricated via a synergistic strategy combining polyaniline (PANI) nanofiber templating and ZnCl₂ selective etching. The dual-functional design simultaneously resolves the conflict between mesopore development and active-site preservation in biomass-derived carbons. Research has shown that PANI introduction promotes the formation of a nanofibrous structure in chitosan. Meanwhile, ZnCl₂ enables selective etching of mesoporous structures during high-temperature calcination, which significantly enhances catalytic performance. The highest biodiesel yield (95.6%) was obtained under specific conditions (2 vol% ammonium persulfate dosage, 35% ZnCl₂ content, 1:3 M ratio of ammonium persulfate to aniline, hydrothermal reaction temperature of 160 ℃, calcination temperature of 600 ℃, methanol-oil molar ratio of 9:1, catalyst content of 1.5 wt%, reaction temperature of 65 ℃ and reaction time of 6 h). It exhibited good adaptability to waste cooking oil (88.08% yield with 10% FFA) and retained over 60% activity after 5 cycles. Ultimately, the simple synthetic method described in this study provides a technique for producing unique active mesoporous carbon from biomass carbon aerogels.