多活性中心的多金属氧酸盐设计合成及催化性能研究

发布时间：2018-07-17 08:20

【摘要】：现如今,非均相催化剂在酯化反应和酯的氧化酸化反应中有重要的作用。多金属氧酸盐有很强的布朗斯特酸性并且以均相或非均相催化剂在酯化反应和酯的氧化酸化反应中有广泛的应用。具体研究内容如下:1.本章设计了一个新型的酸碱三中心多孔结构的新型催化剂HPA/Ti/chitosan并应用于酯化反应中。结果表明,固载型催化剂HPA/Ti/chitosan中催化活性位点H3PW12O40基本结构未发生改变,由于氢键作用使H3PW12O40能很好的均匀分散在壳聚糖表面上。在酸催化酯化反应中,最佳反应条件为:反应温度65oC,醇酸摩尔比为13:1,催化剂用量为5wt%,反应7 h并且使酯化反应的转化率高达97.3%,重复五次后能实现转化率由最初的97.3%到94.2%,仅降低3.1%,说明重复使用五次仍具有较高的催化活性。2.本章阐述了一个多功能化的多酸催化剂——H_2PW/FeTCPP,将此催化剂应用于酯化反应中,在反应条件为反应温度65oC,醇酸摩尔比为15:1,催化剂用量为7wt%,反应7 h时转化率为91.3%。此外它的疏水性使其能够多次利用从而减少了原料成本。3.H_2PW/FeTPP中的卟啉结构具有很好的氧化功能,将催化剂应用于醇的氧化酸化反应中表现出高的催化效果。结果表明,在反应条件为:催化剂用量为250wt%,反应温度45oC,反应时间为8h的条件下当正丁醇的转化率和产率达到最大值——100%和76.4%,重复六次实验之后催化效果也没有明显变化。4.通过实验,我们阐述了一个多功能化的多酸催化剂——H_2PMo/FeTPP,这种催化剂表面上既有氧化集团又有酸性集团,使得反应同时在氧化的同时还能自身发生酯化反应。在反应条件为:催化剂用量300wt%,反应温度45oC,反应时间为7h的条件下,正丁醇的转化率和产率达到最大值——100%和69.4%。此外它的疏水性使其能够多次利用从而减少了原料成本。
[Abstract]:Nowadays, heterogeneous catalysts play an important role in esterification and oxidative acidification of esters. Polyoxometalates have strong Brownst acidity and are widely used in esterification and oxidative acidification of esters with homogeneous or heterogeneous catalysts. The specific contents of the study are as follows: 1. In this chapter, a novel catalyst HPA / Ti / chitosan with three center porous structure was designed and applied in esterification. The results showed that the basic structure of H3PW12O40 in HPA / Ti / chitosan was not changed, and H3PW12O40 was well dispersed on chitosan surface due to hydrogen bonding. In acid catalyzed esterification, The optimum reaction conditions are as follows: reaction temperature 65 OC, molar ratio of alcohol to acid 13: 1, catalyst dosage 5 wk, reaction time 7 h and the conversion rate of esterification up to 97.30.After repeated for five times, conversion can be achieved from the initial 97.3% to 94.2%, with only a decrease of 3.1%. It still has high catalytic activity. 2. In this chapter, a multifunctional polyacid catalyst, H _ 2PW _ p / FeTCPP, was used in esterification reaction. The reaction conditions were as follows: reaction temperature 65 oC, molar ratio of alcohol to acid 15: 1, catalyst dosage 7 wt.The conversion was 91.3% at 7 h. In addition, its hydrophobicity enables it to be used many times, thus reducing the cost of raw materials. 3. The porphyrin structure in the FeTPP has good oxidation function, and the catalyst used in the oxidation and acidification of alcohols has a high catalytic effect. The results showed that the conversion and yield of n-butanol reached the maximum value of -100% and 76.4% under the conditions of catalyst dosage of 250 wtt, reaction temperature of 45oC and reaction time of 8h, and the catalytic effect did not change significantly after six experiments. Through experiments, we have described a multifunctional polyacid catalyst H _ S _ 2PMo / FeTPP, which has both oxidation group and acid group on the surface of the catalyst, which makes the reaction take place simultaneously with oxidation and esterification. The conversion and yield of n-butanol reached the maximum value of -100% and 69.4% respectively under the conditions of catalyst dosage of 300wtwt, reaction temperature of 45oC and reaction time of 7h. In addition, its hydrophobicity enables it to be used many times, thus reducing the cost of raw materials.
【学位授予单位】：东北师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36

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