固体酸催化剂MxOy-ZrO2-Al2O3催化果糖分解制备5-羟甲基糠醛的研究

Preparation of 5-hydroxymethylfurfural from fructose catalyzed by solid acid catalysts MxOy-ZrO_2-Al_2O_3

采用溶胶-凝胶法制备了MxOy-ZrO2-Al2O3固体酸催化剂,通过催化果糖分解制备5-羟甲基糠醛(5-HMF)的反应对催化剂的催化性能进行评估。结果表明,相对于其他MxOy-ZrO2-Al2O3催化剂,La2O3-ZrO2-Al2O3具有更高的催化活性。在其催化作用下,于120℃与二甲基亚砜溶液反应75 min,5-HMF的收率高达74.91%,生成5-HMF的选择性为77.71%。研究发现La2O3-ZrO2-Al2O3的晶体结构对催化活性有着显著影响,随着催化剂由高结晶结构向无定形转变时,其催化活性出现大幅度减弱。此外,La2O3-ZrO2-Al2O3还具有优异回收性能,重复使用2次后其催化活性几乎保持不变。

MxOy-ZrO2-Al2O3 solid acid catalysts is prepared by sol-gel method. The catalytic property of MxOy-ZrO2-Al2O3 is evaluated by catalytic conversion of fructose to 5-hydroxymethylfuffural （5-HMF）. The results indicate that La2 03 -ZrO2 -A12 03 shows superior catalytic activity comparing with other MxOy-ZrO2-Al2O3 solid acid catalysts. The yield of 5-HMF can reach up to 74. 91% with 79. 9% of selectivity to 5-HMF when the degradation of fructose is catalyzed by La2O3-ZrO2-Al2O3 in dimethylsulfoxide for 75 minutes at 120℃. Further studies show that the crystal structure ofLa2O3-ZrO2-Al2O3strongly affects its catalytic activity. The catalytic activity is markedly decreased when the crystal structure turns from higher crystallization degree to amorphous. In addition, La2O3-ZrO2-Al2O3 also exhibits excellent recycle ability. The catalyst can be recycled 2 times without loss of catalytic activity.