Development of TiO2-Carbon Composite Acid Catalyst for Dehydration of Fructose to 5-Hydroxymethylfurfural

Abstract

A TiO2-Carbon (TiO2C) composite was prepared using the microwave-assisted method and sulfonated using fuming sulfuric acid to produce a TiO2C solid acid catalyst. The prepared solid acid catalyst was characterised using scanning electron microscopy, Brunauer-Emmett-Teller analysis, Fourier transform infrared spectroscopy, and X-ray diffraction. Crystallinity analysis confirmed that TiO2C has an anatase structure, while analysis of its morphology showed a combination of spheres and particles with a diameter of 50 nm. The TiO2C solid acid catalyst was tested for use in the catalytic dehydration of fructose to 5-hydroxymethylfurfural (5-HMF). The effect of reaction time, reaction temperature, catalyst dosage, and solvent were investigated against the 5-HMF yield. The 5-HMF yield was found to be 90% under optimum conditions. The solid acid catalyst is very stable and can be reused for four catalytic cycles. Hence, the material has great potential for use in industrial applications and can be used for the direct conversion of fructose to 5-HMF because of its high activity and high reusability.

Microporous and mesoporous structure catalysts for the production of 5‐hydroxymethylfurfural (5‐HMF)

“…The microwave heating starts from the core of the molecules and allows controllable reaction parameters for producing a high yield of targeted product and reduce the side reactions 44,142,143 . Songo M. M. et al 41 found 53.4% of HMF yield from fructose using the TiO 2 in a DMSO solvent system using the autoclave high‐performance microwave reactor. They stated that the catalytic activity of the TiO 2 catalyst depends on its morphological and structural properties, and thus, the use of modified titania carbon as composite acid catalysts can maximize the conversion of fructose to HMF 41 .…”

“…Songo M. M. et al 41 found 53.4% of HMF yield from fructose using the TiO 2 in a DMSO solvent system using the autoclave high‐performance microwave reactor. They stated that the catalytic activity of the TiO 2 catalyst depends on its morphological and structural properties, and thus, the use of modified titania carbon as composite acid catalysts can maximize the conversion of fructose to HMF 41 . As a result, Songo et al 41 discovered that the sulfonated TiO 2 , as shown in Figure 16, has an irregular shape of TiO 2 that was homogeneously distributed onto the carbon surface, resulting in a 95% HMF yield produced under microwave‐assisted heating method and sulfonated with concentrated sulfuric acid.…”

“…Unfortunately, this conversion process gives a relatively low product selectivity and yield due to the formation of byproducts 16,28 . The catalytic performance of the glucose dehydration strongly depends on various operating conditions to achieve a higher production rate of HMF, such as reaction temperature, reaction time, types of catalyst used, catalyst loadings, substrate concentration, solvent selection, and its concentration 6,41,105 …”

“…21,34 However, over the decades, homogeneous catalysts exhibit several shortcomings include the difficulties and high cost for complete-separation and recovery process of catalysts from the product, increased risk for equipment corrosion, the generation of environmental pollution risk and these homogeneous catalysts have limited application which not suitable for broad industrial/commercial-scale application. 25,[35][36][37][38][39][40][41][42] The simple summaries of previous studies for the catalytic…”

“…These catalysts include strong mineral‐acids catalysts, zeolites, metal oxides and minerals, functionalized silica materials, and heteropolyacids 21,34 . However, over the decades, homogeneous catalysts exhibit several shortcomings include the difficulties and high cost for complete‐separation and recovery process of catalysts from the product, increased risk for equipment corrosion, the generation of environmental pollution risk and these homogeneous catalysts have limited application which not suitable for broad industrial/commercial‐scale application 25,35‐42 . The simple summaries of previous studies for the catalytic conversion of HMF are summarized in Table 1 for readers to find the details readily.…”