Biomass-derived sulfonated polycyclic aromatic carbon catalysts for biodiesel production by esterification reaction

Sulfonated polycyclic aromatic carbon (SPAC) catalysts have specific surface characteristics owing to the presence of two types of functional groups: SO3H (sulfonic) and oxygen-containing functional groups (COOH and OH groups). Oxygen-containing functional groups provide a synergistic effect to the sulfonic group, resulting in a high total acid density and enhanced catalytic activity of SPAC. Owing to the high acid density, SPAC catalysts are used for various applications such as organic transformations, electrocatalysis and water treatment. The natural abundance of raw materials, easy processing for catalyst fabrication, excellent catalytic performance and high thermal and chemical stability make SPAC cost-effective and environmentally benign. Biomass-derived heterogeneous catalysts possess unique surface characteristics, high reusability and low cost owing to their easy accessibility, along with various environmental benefits. This review demonstrates biodiesel production using oleic acid as a feedstock material catalyzed by biomass-derived SPAC catalysts. Additionally, various parameters such as catalyst synthetic parameters, esterification reaction parameters, the esterification reaction mechanism and catalytic stability, which affect the catalytic performance and esterification efficacy, are discussed. Finally, the future scope for developing novel SPAC catalysts has been demonstrated for young researchers in this field.

Automated summary

Sulfonated polycyclic aromatic carbon (SPAC) catalysts with specific surface characteristics have been widely used in various applications due to their high acid density and enhanced catalytic activity. Biomass-derived SPAC catalysts have unique surface characteristics, high reusability, and low cost, making them environmentally friendly options for biodiesel production. This review discusses the catalytic performance, reaction parameters, mechanism, and future development of SPAC catalysts for biodiesel production.