Synthesis of ordered hierarchically mesoporous/microporous carbon materials via compressed CO2 for fructose-to-HMF transformation

Well-ordered hierarchically mesoporous/microporous carbon materials have been successfully fabricated by using dual soft-templating approach through compressed CO2. Pluronic F127 and different type of surfactants, including nonionic, cationic, and anionic surfactants, were used as dual templates to investigate the influence on the morphology and nanostructure of the as-prepared carbon samples. TEM, SEM, N2 sorption, wide-angle and small-angle XRD analysis were employed to reveal the well-ordered hierarchically micro-mesoporous structure with 2D hexagonal symmetry by using compressed CO2. The prepared HPC samples with different pressures as the catalyst carriers have been functioned by chlorosulfonic acid for the fructose conversion into HMF. Chlorosulfonic acid concentration, catalyst dosage and reaction temperature have been optimized for fructose-to-HMF transformation with the obtained catalyst. The performances of as-made HPC–SO3H samples in HMF yield and reaction rate of fructose-to-HMF transformation have been investigated. The stability of the samples was also conducted in the dehydration of fructose to HMF for five cycles. The possible catalytic mechanism by using hierarchically porous carbon materials as catalyst support for fructose-to-HMF transformation was proposed.