Cu-Fe类水滑石催化合成糠醛1,2-丙二醇缩醛

采用共沉淀法制备了不同n(Cu):n(Fe)的Cu-Fe类水滑石催化剂,采用X射线衍射、扫描电子显微镜和NH_3程序升温脱附等方法对催化剂进行了表征。将Cu-Fe类水滑石用于催化糠醛与1,2-丙二醇反应合成了糠醛1,2-丙二醇缩醛,探讨了催化剂组成、原料配比、催化剂用量和反应时间对合成反应的影响。实验结果表明,Cu-Fe类水滑石对该反应的催化活性和选择性都很高,是合成糠醛1,2-丙二醇缩醛的良好催化剂;以n(Cu):n(Fe)=3的Cu-Fe类水滑石为催化剂,在糠醛用量0.12 mol,n(1,2-丙二醇):n(糠醛)=1.5、催化剂用量2.60%(相对于糠醛的质量分数)、带水剂环己烷用量5 mL、反应时间5 h、反应温度95～100℃的条件下,糠醛的转化率可达81 7%,糠醛1,2-丙二醇缩醛的选择性为99.7%。同时根据实验结果初步提出了该反应的催化机理。

Synthesis of Furfural 1,2-Propanediol Acetal Catalyzed by Cu-Fe Hydrotalcite-Like Compounds

CuFe-hydrotalcite-like compound (CuFe-HTLcs) with different n (Cu) : n (Fe) were prepared by coprecipitation and used as catalyst in synthesis of furfural 1,2-propanediol acetal from furfural and 1,2-propanediol. The catalyst was characterized by means of XRD, SEM and NH_3-TPD. Effects of catalyst composition, ratio of starting materials, catalyst dosage and reaction time on conversion of furfural and selectivity to furfural 1,2-propanediol acetal were discussed. CuFe-HTLcs showed high catalytic activity and selectivity in synthesis of furfural 1,2-propanediol acetal. Under reaction conditions : CuFe-HTLcs as catalyst (n (Cu) : n (Fe) = 3), furfural 0. 12 tool, n (1,2-propanediol) : n(furfural) 1.5, catalyst dosage 2.60% (based on mass of furfural) , cyclohexane as water entrainer 5 mL, reaction temperature 95 - 100 ℃ and reaction time 5 h, conversion of furfural and selectivity to furfural 1,2-propanediol acetal reached 81.7 % and 99.7 %, respectively. Catalytic mechanism of the reaction was tentatively proposed according to results of the experiments.