Engineering Zeolite Acidity and Porosity for Improved Esterification: A Review of Mechanisms, Kinetics, and Sustainability Processes

Esterification, the reaction between carboxylic acids and alcohols that produces esters and water, plays a vital role in many industries, especially in biodiesel and pharmaceutical manufacturing. Traditional methods using homogeneous mineral acids pose environmental issues, prompting the search for sustainable alternatives—solid acid catalysts. Zeolites offer unique structural advantages, including shape selectivity and adjustable acidity, which improve reaction efficiency and reduce waste. This review provides a detailed examination of how zeolite topology—particularly pore structure and connectivity—influences the kinetics of long-chain fatty acid (LCFA) esterification. It investigates the optimization of acid sites via modifications to the silicon-to-aluminum ratio (Si/Al), ion exchange, and pore engineering to improve mass transfer. The study investigates key reaction mechanisms, specifically the Langmuir–Hinshelwood (LH) and Eley–Rideal (ER) models, to address issues such as mass-transfer limitations and water inhibition. The paper highlights recent advances in sustainable catalyst design, such as hierarchical zeolites and membrane-integrated reactors, for converting biomass-derived feedstocks into valuable esters. It also discusses current research challenges and suggests future directions, including the use of 3D-printed monoliths and machine learning integration, to develop next-generation, eco-friendly zeolite catalysts.