摘要
采用浸渍法制备五氧化二铌(Nb_(2)O_(5))负载三氧化钨(WO_(3))固体酸催化剂,用XRD、EDS、TEM、NH3-TPD、Py-IR、BET、BJH对催化剂的结构、组分、形貌、酸性、比表面积及孔径等进行表征;并将其用于催化果糖转化为5-羟甲基糠醛(HMF)的反应,对WO_(3)负载量、反应时间、反应温度、催化剂用量等影响因素进行考察。结果表明,WO_(3)负载量对催化剂结构、酸性以及催化活性均有影响。WO_(3)负载量为5%~25%时,随着WO_(3)负载量的增加,WO_(3)分子从表面分散的非晶态转变为结晶态WO_(3),且Nb_(2)O_(5)上的WO_(3)产生更多的强酸位点,使催化剂的Brønsted酸含量增加,从而使果糖的转化率得到提高;但结晶WO_(3)却不利于HMF的生成。当WO_(3)的负载量为5%时,在催化剂加入量为100 mg,果糖1.2 g,水/仲丁醇(体积比2∶3)为溶剂,170℃条件下反应1 h,HMF选择性较高,为85.4%,收率可达49.6%。
A series of niobium pentoxide(Nb_(2)O_(5))supported tungsten trioxide(WO_(3))solid acid catalysts were prepared by impregnation method.Structure,components,morphology,acidity,specific surface area and porosity of the catalysts were characterized by XRD,EDS,TEM,NH3-TPD,Py-IR,BET,BJH.And catalytic properties in conversion of fructose to 5-hydroxymethylfurfural(HMF)were studied.Factors such as tungsten trioxide loading,reaction time,reaction temperature,and catalyst dosage were investigated.It was found that WO_(3)loading had an important effect on the structure,acidity and catalytic properties of the catalysts.With the increase of WO_(3)loading from 5%to 25%,tungsten oxide molecules changed from amorphous WO_(3)dispersed the surface to crystalline WO_(3),and an appropriate amount of WO_(3)on Nb_(2)O_(5)generated a large number of strong acidic sites,which increased the content of Brønsted acid sites in the catalyst and thus improved the conversion rate of fructose.However,crystalline WO_(3)was not conducive to the production of HMF.The selectivity and yield of HMF could reach 85.4%and 49.6%under the condition of reaction time of 1 h,reaction temperature of 170℃,dosage of the catalyst(WO_(3)loading of 5%)being 100 mg and fructose being 1.2 g in water/2-butanol(volume ratio of 2∶3).
作者
丁佳晶
赵芷言
夏斐斐
杨凤丽
DING Jiajing;ZHAO Zhiyan;XIA Feifei;YANG Fengli(School of Chemical and Environmental Engineering,Jiangsu University of Technology,Changzhou 213001,Jiangsu,China)
出处
《精细化工》
EI
CAS
CSCD
北大核心
2021年第3期559-565,共7页
Fine Chemicals
关键词
固体酸催化剂
五氧化二铌
三氧化钨
果糖
5-羟甲基糠醛
催化技术
solid acid catalyst
niobium pentoxide
tungsten trioxide
fructose
5-hydroxymethylfurfural
catalytic technology
