High value-added fuel additive production from waste bio-glycerol over a versatile nanohybrid catalyst†
Abstract
This study presents a pioneering nanohybrid catalyst featuring hierarchically porous dual-functional (acid–base) active sites, which is a versatile catalyst for the crucial bio-glycerol acetalization reaction. The nanohybrid catalyst demonstrated remarkable efficiency in converting bio-diesel derived waste glycerol into excellent green fuel additive ‘solketal,’ achieving an unprecedented yield of approximately 99%. Insights into the structural properties and the relationship between the structure and properties of the catalyst were obtained through various characterization techniques, including FTIR spectroscopy, XRD, NH3-TPD, CO2-TPD, 27Al-NMR spectroscopy, SEM, TEM, UV-Vis spectroscopy, and X-ray photoelectron spectroscopy. The hybrid catalyst shows several highly desirable properties, including enhanced acidity, a strong affinity for reactants, mesoporosity, stability, and the proximity of potent acidic and basic sites. Simplicity, cost-effectiveness, exceptional recyclability, and resistance to moisture make the synthesized MgAl-oxide/HZSM-5 (MAZ) nanohybrid catalyst an appealing candidate for potential commercial applications in bio-refinery processes.