Optimization of reaction parameters by using response surface methodology (RSM) for the selective dehydration of glucose to 5-hydrox- ymethylfurfural (5-HMF), a valuable platform chemical over a mesoporous TiO2 catalyst in dimethylsulfoxide (DMSO) medium

A highly active and selective mesoporous TiO2 was developed by the sol-gel hydrolysis technique for the selective transformation of glucose to 5-hydroxymethylfurfural (5-HMF). The catalytic performance was tested in a glass tube reactor, and the reaction parameters were optimized using response surface methodology (RSM). The best -optimized reaction conditions were obtained using four-factors, four-responses, and the 5-level central composite design (CCD) integrated with the desirability approach. At the optimum reaction condition, RSM predicted complete conversion of glucose and a very high 5-HMF yield of-56% in the dimethylsulfoxide (DMSO) solvent. The predicted yield of other major products, including formic acid (FA) and levulinic acid (LA), was-18% and-2%, respectively. The empirical process model developed by RSM was validated by the experimental data generated. Experimental results demonstrated that the TiO2 catalyst developed can easily be recycled with a constant glucose conversion and 5-HMF yield. Further, a new liquid-liquid extraction method (LLE) is proposed to extract 5-HMF from the product. The results depicted that 5-HMF can easily be extracted from the product mixture with very high purity (-96%). Additionally, the Power-Law kinetic study suggested that the conversion of glucose over TiO2 followed the first-order kinetics, and the calculated activation energy was 67.5 kJ mol-1.

Automated summary

A highly active and selective mesoporous TiO2 catalyst was developed for the conversion of glucose to 5-HMF. The reaction conditions were optimized using response surface methodology, and the catalyst was proven to be recyclable and the 5-HMF can be easily extracted from the product mixture with high purity.