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以超临界CO_2为溶剂,以经磷酸浸渍碳化、浓H2SO4磺化制备的油茶壳炭磺酸为催化剂,将D-果糖脱水转化制备5-HMF。利用中和滴定、元素分析、红外光谱、Raman光谱对催化剂进行了表征。在220℃、浸渍10 h后再磺化3 h,-SO_3H基团成功键合到无定形炭基体上,得到的油茶壳炭磺酸催化剂表面酸值最高可达1.801 0 mmol·g-1。相比无溶剂或选取有机溶剂、浓硫酸为催化剂的反应体系而言,在超临界CO_2中,D-果糖在120℃反应30 min,5-HMF的得率最高可达47%。实验结果为超临界CO_2在生物质催化转化领域的应用及油茶壳的高附加值利用提供了理论和实验参考。
Using supercritical CO_2 as solvent, 5-HMF was prepared by dehydrating D-fructose with oleic-charcoal sulfonic acid prepared by phosphoric acid impregnation carbonization and concentrated H2SO4 sulfonation. The catalysts were characterized by neutralization titration, elemental analysis, infrared spectroscopy and Raman spectroscopy. At 220 ℃ for 10 h, sulfonation was carried out for 3 h and the -SO_3H group was successfully bonded to the amorphous carbon matrix. The surface acid number of the obtained catalyst was up to 1.801 mmol · g-1. Compared with solvent-free or organic solvent-concentrated sulfuric acid as catalyst, D-fructose reacted at 120 ℃ for 30 min in supercritical CO_2, yield of 5-HMF was up to 47%. The experimental results provide theoretical and experimental references for the application of supercritical CO_2 in the field of biomass catalytic conversion and high value-added utilization of Camellia.