Au/Al_(2)O_(3)催化剂催化5-羟甲基糠醛加氢制备2,5-呋喃二甲醇

HYDROGENATION OF 5-HYDROXYMETHYLFURFURAL TO 2,5-BIS(HYDROXYMETHYL)FURAN ON Au Al_(2)O_(3)CATALYST

为探究生物质醛加氢的高效催化剂,以贵金属Au为活性组分,采用沉积-沉淀法制备了负载型Au/Al_(2)O_(3)催化剂,通过X射线粉末衍射、透射电镜、X射线光电子能谱、静态低温氮吸附容量法和NH_(3)程序升温脱附等表征技术对催化剂形貌进行分析,并将Au/Al_(2)O_(3)催化剂应用于5-羟甲基糠醛(HMF)加氢合成2,5-呋喃二甲醇(BHMF)的反应。考察了催化剂制备所用沉淀剂种类、催化剂的Au负载量以及反应温度、反应压力和反应时间对反应性能的影响,并对催化剂循环稳定性进行分析。结果表明:活性金属Au对该反应有较高的催化活性,且沉淀剂种类对Au颗粒粒径和Au负载量有显著影响。当沉淀剂为NaOH和Na_(2)CO_(3)的混合液(质量比为1∶1)、Au负载量(w)为2.0%时,在反应温度为100℃、H_(2)压力为3.0 MPa、反应时间为4 h的条件下,以0.30 g催化剂催化2.4 mmol HMF加氢制备BHMF,HMF质量转化率达92.1%,BHMF质量选择性达92.0%。

In order to explore the high efficiency catalyst for the hydrogenation of biomass aldehyde,the Au/Al_(2)O_(3)catalyst was prepared by precipitation and deposition method with noble metal Au as the active component.The morphology of the catalyst was characterized by X-ray powder diffractometer,transmission electron microscopy,X-ray photoelectron spectroscopy,static low temperature nitrogen adsorption capacity method and NH_(3) programmed temperature desorption.The Au/Al_(2)O_(3)catalyst was applied to the hydrogenation of 5-hydroxymethylfurfural(HMF)to 2,5-bis(hydroxymethyl)furan(BHMF).The effects of precipitator type,Au loading capacity,reaction temperature,reaction pressure and reaction time on the catalytic performance were investigated,and the cyclic stability of the catalyst was analyzed.The results showed that the active metal Au had a high catalytic activity for the reaction,and the type of precipitator had a significant effect on the particle size and loading rate of Au particles,leading to a certain difference in activity.When the precipitant was a mixture of NaOH and Na_(2)CO_(3)(mass ratio of 1∶1),the Au loading capacity was 2.0%,the reaction temperature was 100℃,the H_(2) pressure was 3.0 MPa,and the reaction time was 4 h,0.30 g catalyst could catalyze 2.4 mmol HMF to BHMF.The mass conversion of HMF was 92.1%and the mass selectivity of BHMF was 92.0%.