Mesoporous Bifunctional K

Mesoporous metal oxides are highly effective catalysts for biodiesel production due to their large surface area and adjustable pore structures, which enhance mass transfer and catalytic activity. In this study, a mesoporous K₂O catalyst was prepared using chitosan, a natural polymer, as a template. Chitosan was first dissolved in a mild acetic acid solution and mixed with potassium nitrate at an optimized ratio. The mixture was stirred and then added dropwise into a sodium hydroxide solution, inducing the formation of solid spherical beads through chemical bonding. The beads were then dried, and calcined at 700 °C for 2 h. This calcination step removed the organic chitosan, creating a porous structure, while converting potassium compounds into active catalytic species including K₂O, K₂O₂, and K₂CO₃·1.5H₂O, which also helped maintain the bead morphology. SEM analysis revealed a dense, porous structure, while the catalyst’s bifunctional nature was confirmed by a total basicity of 1.346 mmol/g and total acidity of 1.515 mmol/g. The optimised synthesis conditions yielded a maximum biodiesel yield of 95.26%, demonstrating the catalyst’s potential for efficient biodiesel production.