Realizing Direct Conversion of Glucose to Furfurals with Tunable Selectivity Utilizing a Carbon Dot Catalyst with Dual Acids Controlled by a Biphasic Medium

Developing a cost-effective processing approach for generating fuel-precursor chemicals such as 5-hydroxymethylfurfural (HMF) and furfural has been researched to a great deal over the last few years. Typically, these chemicals are produced using a different carbohydrate source, like xylose for furfural and glucose for HMF. Herein, we report the significant formation of these furan chemicals using glucose over the fine-tuned Fe2+@SO3-CD nanocomposite. The catalyst exhibiting two different acidic sites, namely Lewis and Brønsted, developed by the iron (II) metal and sulfonate groups, respectively, offered a synergistic effect on the glucose decomposition into furans. Mechanistically, the iron (II) Lewis metal acid sites play a vital role in the significant formation of furfural. In addition, the biphasic system comprising THF/H2O influenced a selective HMF and furfural formations, achieving as high as 85% HMF (94% selectivity) in 1:2 THF/H2O and 56% furfural (90% selectivity) in 1:1 THF/H2O. The recyclability study disclosed that the catalyst is effective for 4 recycles. The green metrics analysis of the solid acid catalysis suggested that setup is a greener method for furans production. Moreover, the catalysis reaction can be upscaled based on the use of cheaper precursors and a facile method of catalyst preparation.