Exploring catalytic systems for furfural upgradation to value-added products

Abstract

As the world moves toward sustainable and renewable resources, efficient biomass conversion processes have become a key area of focus. Furfural (FFR), a platform chemical derived from lignocellulosic biomass, presents significant potential for replacing fossil-derived products with high-value chemicals and fuels. This thesis explores the design and optimization of catalytic systems for converting FFR into value-added products such as 2-methylfuran (2-MeF) and furfuryl alcohol (FAL), contributing to a greener chemical industry. Both traditional hydrogenation using molecular hydrogen (H2) and alternative transfer hydrogenation approaches using nonconventional hydrogen sources are examined, aiming to develop more sustainable biomass conversion processes. A variety of catalytic systems were tested, including bimetallic catalysts, mixed metal oxides, and supported metal-incorporated mesoporous silica, to enhance catalyst performance and selectivity in FFR valorization. Detailed material characterization was carried out using techniques such as X-ray diffraction (XRD), Brunauer-Emmett-Teller surface area analysis (BET), temperature-programmed desorption (TPD), scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), and highresolution transmission electron microscopy (HRTEM). These analyses confirmed the successful synthesis and structural properties of the catalysts. Optimization of process parameters, such as space-time and reaction temperature, along with time-on-stream (TOS) studies, revealed promising results. TiO2-supported Cu-Ni bimetallic catalysts exhibited impressive selectivity for converting FFR to 2-MeF, achieving up to 84.5% selectivity at 200 °C using a 10%Cu- 10%Ni/TiO2 catalyst. Additionally, Cu-Fe mixed oxide catalysts with equimolar ratios of Cu and Fe demonstrated excellent performance in FFR hydrodeoxygenation, achieving up to 90% selectivity for 2-MeF at 230 °C under ambient H₂ pressures. The thesis also highlights the use of mesoporous silica derived from rice husk ash, with metals incorporated to create highly efficient catalysts. The Cu-supported Zrincorporated mesoporous silica catalyst (Cu@Zr-MS) achieved FFR conversion rates of 90% and maintained FAL yields of approximately 85% over extended reaction periods. Further exploration of transfer hydrogenation using Mg-Fe mixed oxide catalysts showed that the optimal Mg/Fe ratio of 4 delivered a 79.8% selectivity for 2- MeF and 85.2% FFR conversion over a 4-hour reaction time at 400 °C. This research underscores the potential of innovative catalytic systems for developing more sustainable and efficient biomass conversion processes, offering valuable insights into advancing the green chemical industry