Recent Advances in Electrocatalytic Transesterification: Enhancing Biodiesel Synthesis for Sustainable Energy

The depletion of fossil fuels and the escalating environmental degradation have intensified the global search for sustainable and renewable energy alternatives. Biodiesel, either used directly or blended with petrodiesel, presents a more environmentally favorable option for diesel engines, owing to its superior combustion efficiency, biodegradability, low sulfur content, high cetane number, and high flash point. However, traditional biodiesel production methods, such as acid-catalyzed transesterification, which requires significant acid consumption, and supercritical transesterification, which operates at elevated temperatures, are limited by their complexity and high production costs. In contrast, electrocatalytic transesterification represents a promising and bio-based approach for biodiesel synthesis. This method utilizes electrochemical mechanisms to drive the transesterification reaction under milder conditions, with or without the use of a catalyst, significantly enhancing reaction efficiency and selectivity. Electrocatalytic processes have demonstrated efficiency across various feedstocks, including palm oil, lemon seed oil, sunflower oil, corn oil, and alternative resources such as waste cooking oil (WCO), chicken fat, vegetable oil refinery waste, and algal oil, WCO, chitosan gel, plastic waste, and biomass-derived biochar incorporated with metal or metal–oxide nanoparticles. This review critically explores the electrocatalytic synthesis of biodiesel from a range of raw materials, emphasizing its potential for advancing sustainable energy production. Furthermore, this approach not only offers a cleaner energy solution but also contributes to environmental protection by reducing greenhouse gas emissions. The review emphasizes the critical role of electrocatalytic transesterification in advancing the development of biodiesel as a sustainable and energy-efficient alternative in addressing global energy challenges.