【摘要】 采用密度泛函理论,使用Materials Studio的DMol3模块,计算了1,1,1,3,3-五氯丙烷(HCC-240fa)气相氟化生成1,3,3,3-四氟丙烯(HFO-1234ze)反应体系中各反应的反应焓变和Gibbs自由能变;并通过比较不同温度下各反应的反应焓变和Gibbs自由能变,对反应过程进行了热力学分析.结果表明:HCC-240fa经过氟氯交换和脱HCl反应合成中间体1-氯-3,3,3-三氟丙烯(HCFC-1233zd)的反应为热力学上可自发进行的反应,且产物以HCFC-1233zd(E)为主;低温有利于HCFC-1233zd与HF进行加成反应生成1-氯-1,3,3,3-四氟丙烷(HFC-244fa),HFC-244fa可与HF进行氟氯交换反应合成1,1,1,3,3-五氟丙烷(HFC-245fa);高温有利于HCFC-1233zd进行氟氯交换反应合成HFO-1234ze;HFC-244fa脱HCl反应和HFC-245fa脱HF反应均需要较高的反应温度,主产物为HFO-1234ze(E). 更多还原

【Abstract】 The changes of the enthalpy and Gibbs free energy during the synthesis of 1,3,3,3-tetrafluoropropene( HFO-1234ze) via gas-phase fluorination of 1,1,1,3,3-pentachloropropane( HCC-240fa) were estimated based on density functional theory( DFT) by using Materials Studio DMol 3 calculations. By comparing the changes of the enthalpy and Gibbs free energy as a function of reaction temperature for each independent reaction,thermodynamics of the reaction process were analyzed. The results showed that the... 更多还原