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合成了一种新的固体酸催化剂3-吡啶磺酸-磷钼酸(PSA-HPM),利用X-射线粉末衍射(XRD)、红外光谱(FT-IR)、热重(TG)以及电位滴定等方法对其进行分析,并以油酸与甲醇的酯化反应为探针反应,考察了该催化剂对酯化反应的催化性能,系统探讨了催化剂用量、醇酸物质的量比、反应时间、反应温度以及催化剂重复利用等对催化反应的影响。结果表明,PSA-HPM具有典型的Keggin结构,在T<352℃时表现出较好的热稳定性,同时具有较高的酸度;PSA-HPM在催化酯化反应中表现出了高的催化活性。当醇酸物质的量比为7∶1、催化剂用量为油酸质量的10 wt%、在80℃反应5 h后油酸甲酯产率达96.5%。PSA-HPM同时表现出好的重复利用性,4次使用后,催化剂的物相以及Keggin结构没有明显变化。
A new solid acid catalyst 3-pyridine sulfonic acid-phosphomolybdic acid (PSA-HPM) was synthesized and characterized by X-ray powder diffraction (XRD), infrared spectroscopy (FT-IR), thermogravimetric (TG) and potentiometric titration The esterification reaction between oleic acid and methanol was used as the probe reaction. The catalytic performance of the catalyst for esterification reaction was investigated. The effects of the amount of catalyst, the molar ratio of alkyd to acid, the reaction time, Reaction temperature and catalyst reuse on the catalytic reaction. The results showed that PSA-HPM possesses typical Keggin structure, shows good thermal stability at T <352 ℃ and high acidity. PSA-HPM shows high catalytic activity in the esterification reaction . When the ratio of alkyd is 7:1, the amount of catalyst is 10 wt% of oleic acid, the yield of methyl oleate reaches 96.5% after reacting at 80 ℃ for 5 h. PSA-HPM shows good reusability at the same time. After 4 times of use, the phase of the catalyst and Keggin structure have no obvious change.