Abstract The catalytic activity of a series of vanadyl pyrophosphate (VPP) catalysts with different loadings supported on mesoporous silica KIT-6 was investigated for the dehydration of glucose and fructose into 5-hydroxymethylfurfural (5-HMF). The active phase was synthesized by V2O5 reduction in an alcoholic media followed by calcination of VOHPO4.0.5H2O precursor at 400 °C. The catalysts were characterized by FT-IR spectroscopy, Raman spectroscopy, ICP-OES, X-ray diffraction (XRD), N2 adsorption-desorption analysis, and temperature-programmed desorption (NH3-TPD) techniques as well as SEM, TEM, and X-ray photoelectron spectroscopy (XPS). Among the catalysts, the one containing the lowest percentage of VPP exhibited the best activity in the dehydration reaction. The effect of different parameters such as the loading amount of VPP on the support, the initial amount of carbohydrates and catalyst, reaction temperature, time, and solvent was studied. The highest yields of 5-HMF were obtained to be 79% (145 °C/1 h) and 48% (185 °C/1.5 h) for the fructose and glucose dehydration, respectively. Catalysts were simply separated via centrifugation without significant changes in catalytic activity and reused for additional four runs.

中文翻译：

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焦磷酸氧钒催化剂上碳水化合物脱水成5-羟甲基糠醛

摘要 研究了一系列负载在介孔二氧化硅 KIT-6 上的不同负载量的焦磷酸氧钒 (VPP) 催化剂对葡萄糖和果糖脱水生成 5-羟甲基糠醛 (5-HMF) 的催化活性。活性相是通过在酒精介质中还原 V2O5，然后在 400°C 下煅烧 VOHPO4.0.5H2O 前体来合成的。催化剂通过 FT-IR 光谱、拉曼光谱、ICP-OES、X 射线衍射 (XRD)、N2 吸附-解吸分析和程序升温脱附 (NH3-TPD) 技术以及 SEM、TEM 和X 射线光电子能谱 (XPS)。在催化剂中，含有最低百分比的 VPP 的催化剂在脱水反应中表现出最好的活性。VPP加载量等不同参数对支架的影响，研究了碳水化合物和催化剂的初始量、反应温度、时间和溶剂。对于果糖和葡萄糖脱水，5-HMF 的最高产率分别为 79% (145 °C/1 h) 和 48% (185 °C/1.5 h)。催化剂通过离心简单分离，催化活性没有显着变化，并重新用于额外的四次运行。