One-pot conversion of furfural over acid ZSM-5, beta and USY zeolites - Activity and selectivity to value-added molecules as a function of their textural and acid Properties

• Grant number: 25/10530-4
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: September 01, 2025
• End date: April 30, 2027
• Field of knowledge: Engineering - Chemical Engineering - Chemical Technology
• Principal Investigator: Ernesto Antonio Urquieta Gonzalez
• Grantee: Nathan Pichot
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
• Associated research grant: 21/12394-0 - Sustainable synthetic methods employing catalysis, benign solvents, safer reagents, and bio-renewable feedstock, AP.TEM

Abstract

As well known, most of the fuels applied to produce energy and chemicals or intermediates use petroleum, natural gas, or mineral carbon as raw materials. The use of these fossil materials has been responsible for the strong environmental contamination and for the dramatic global warming. For that reason, it will be urgently necessary to find alternative sustainable sources, also known as green or clean (1,2). In this direction, the Brazilian lignocellulosic biomass has received special attention because it exists as an abundant renewable source, which has low cost, and a great potential to be used as raw material to produce biofuels and biochemicals (1). However, the sustainable conversion of these biochemicals into high-value products will require developing an efficient catalytic process, capable of converting complex and oxygenate precursors (platform molecules) involving complex reaction mechanisms. Compared with homogeneous catalysis, heterogeneous catalysis has the great advantage of minimizing separation and purification steps, also allowing the use of multifunctional catalysts, which will be able to develop a sequential set of reactions into a unique reactor (one-pot). An example of this promising strategy is the application of catalysts simultaneously containing Lewis (L) and Brønsted (B) acid sites, as occurs with catalysts used to convert furfural (platform molecule) into gamma-valerolactone, levulinic acid, stearic levulinates, angelica lactones, ethers or other high-value chemical intermediates, which could be important raw molecules to biofuels and green additives or solvents. Zeolites, simultaneously having Lewis and Brønsted acidity, have shown an important performance in coupling reactions of hydrogen transfer, hydrolysis/alcoholysis, or lactonization of biomolecules (6-10). Nevertheless, due to its microporous system, zeolites present serious constraints to heavy molecules diffusing inside the crystals, thus necessitating to hierarchical its porous system together with adjusting the right L/B acid ratio necessary to reach an optimized yield of a desired high-value molecule from the used platform biomolecule. Thus, the research objectives will be to develop hierarchical ZSM-5, beta, and Y zeolites with a tuned ratio of L/B acid sites to be applied to one-pot convert furfural into high-value chemical intermediates. The research will involve: - To generate intracrystalline mesoporosity in the selected zeolites; - To generate Lewis acidity by isomorphic substitution of structural Al or Si by a Me (IV), as Zr or other. - To characterize the structure, morphology, composition, textural properties, strength, and total acidity and acid nature (L and B). - To evaluate the prepared zeolites in the one-pot conversion of furfural to value-added molecules. - To optimize the reaction conditions, aiming for a high yield. - To determine the kinetic and reaction mechanism as a function of the hierarchical and acidity zeolite characteristics. (AU)