SAPO-34分子筛的合成及催化果糖制5-羟甲基糠醛的应用

Synthesis of SAPO-34 molecular sieve and its application in catalyzing fructose to make 5-hydroxymethyl furfural

制备具有适宜酸性、粒径、比表面积的催化剂是催化果糖制备5-羟甲基糠醛的关键。选择不同模板剂合成了SAPO-34分子筛,并采用SEM、XRD、BET、NH_3-TPD和TG对其进行表征,考察了不同模板剂合成的分子筛催化合成5-羟甲基糠醛的应用效果。结果表明,以三乙胺为模板剂、n(Al_2O_3)∶n(P_2O_5)∶n(SiO_2)∶n(三乙胺)∶n(H_2O)=2∶2∶1∶4∶140、晶化时间为72 h时,合成的SAPO-34分子筛产品粒径比较均匀、酸性最高、结晶度最好,且以该分子筛产品作催化剂催化合成5-羟甲基糠醛的收率最高。在以二甲基亚砜为溶剂、温度为150℃、果糖质量为0.5 g、催化剂质量为0.15 g、二甲基亚砜用量为50 mL的条件下进行反应,5-羟甲基糠醛收率最高可达57%。

Preparation of the catalysts with suitable acidity,particle size and specific surface area is the key in the preparation of 5-hydroxymethyl furfural by catalyzing fructose.In this paper,SAPO-34 molecular sieves are synthesized by using different template agents and are then characterized by SEM,XRD,BET,NH3-TPD and TG.The catalytic effects of the catalysts prepared by different template agents are investigated in the synthesis of 5-hydroxymethylfurfural. Results show that the catalysts prepared under the conditions of using triethylamine as template agent,n（Al2O3） ∶n（P2O5） ∶n（SiO2） ∶n（triethylamine） ∶n（H2O） = 2 ∶2 ∶1 ∶4 ∶140 and 72 h of crystallization time can exhibit uniform particle size,the highest acidity,the best crystallinity and the highest yield of 5-hydroxymethyl furfural. The yield of 5-hydroxymethyl furfural can reach up to 57% when dimethylsulfoxide is used as solvent,reaction temperature is at 150℃,reaction lasts for 90 min and m（fructose） ∶ m（catalyst） ∶ m（dimethylsulfoxide） = 0. 5 ∶0. 15 ∶50.