微波与碳基催化剂协同促进果糖制5-羟甲基糠醛

Microwave(MW)-assisted biomass conversion is a promising method for the production of value-added chemicals. Carbon materials have good chemical stability and dielectric properties, which are ideal catalyst supports and microwave absorbers in the process of MW reaction. In view of this, four carbon materials, including carbon nanotubes(CNT), carbon nanofibers(CNF), carbon black(CB) and activated carbon(AC), were used to catalyst fructose conversion under conventional heating and MW irradiation conditions. The enhancement effects of MW coupling with different supports for the reaction performance were further explored. The heating behaviors of different carbon material suspensions were measured under MW condition, and the difference in their dielectric properties was explained by structural and physical properties. The results show that the MW induced thermal effect of carbon-based catalysts can effectively improve the reaction efficiency. The catalyst with high loss tangent and conductivity tends to have a strong heating ability, which is conductive to transfer MW energy to the catalyst surface. Carbon-based catalysts with high specific surface area, high aspect ratio, low density and high graphitization degree are also beneficial to the generation of thermal effect. In addition, CNT-SA is the most suitable catalyst among the four alternatives. The yield of 5-hydroxymethylfurfural(5-HMF) reaches 96.30% in 10min at 110℃ under MW irradiation, and the catalyst has a good recyclability.