Exploring the potential of graphene-based catalysts for biodiesel production: A comprehensive review of mechanisms, synthesis, promotion, performance, product quality, and environmental sustainability

As the demand for sustainable energy sources grows, there is a need for more efficient and effective biodiesel production processes. Graphene-based materials have emerged as capable and modifiable catalysts due to their unique features, including high surface area and catalytic activity. This review explored the promoted graphene materials, comprising reduced graphene oxide, metal oxide-supported graphene, functionalized graphene, and graphene-based composites, that render them excellent catalysts for the esterification and transesterification reactions. An overview of the reaction mechanisms of different graphene-based catalysts, including acidic, basic, and bi-functional catalysts, is presented. This review exhibits the crucial effect of reaction conditions, including catalyst loadings, temperature, alcohol to oil mole proportion, time, and stirring speed, on the performance of graphene-based catalysts. Crucially, the produced biodiesel consistently meets international quality standards for thermophysical properties and offers significant environmental advantages over petroleum diesel. Ultimately, the advancements in graphene-based catalysis for biodiesel production, as reviewed herein, significantly contribute to the ongoing global efforts toward more efficient and sustainable energy solutions. This exciting and dynamic field possesses perfect potential for future researchers.