Bifunctional rice husk-derived SiO2-Cu-Al-Mg nanohybrid catalyst for one-pot conversion of biomass-derived furfural to furfuryl acetate

Developing one-pot reaction methodologies, which typically require multifunctional catalyst systems, is crucial for sustainable production of bio-derived fuels and chemicals. This work reports one-pot hydrogenation-esterification of furfural to furfuryl acetate using a bifunctional metal-based nanohybrid catalyst, composed of rice husk (RH) derived SiO2, Cu, Al, and Mg species (RHSiO2-Cu-Al-Mg). For comparison, the catalytic efficiency of RHSiO2-Cu and RHSiO2-Cu-Al were tested under similar reaction conditions. Various analytical techniques were used to elucidate the physicochemical, textural, and acid-redox properties of the catalysts. It was found that the RHSiO2-Cu-Al-Mg catalyst contains an optimum amount of acid and redox sites, as illustrated by NH3-TPD and H2-TPR studies, respectively. Especially, Mg addition played a vital role in tailoring acidity of the RHSiO2-Cu-Al catalyst to promote in-situ esterification of furfuryl alcohol with acetic acid to yield furfuryl acetate. As a result, the RHSiO2-Cu-Al-Mg catalyst exhibited the best performance in one-pot conversion of furfural to furfuryl acetate, outperforming various noble metal/silica based catalysts. This study offers potential opportunities for the rational design of novel, bifunctional heterogeneous catalysts for efficient production of bio-derived fuels and value added chemicals.