Selective Dehydrofluorination of 1,1,1,3,3-Pentafluoropropane to Synthesize Tetrafluoropropylene and Trifluoropropyne over the ZnO/Cr2O3 Catalysts
Selective Dehydrofluorination of 1,1,1,3,3-Pentafluoropropane to Synthesize Tetrafluoropropylene and Trifluoropropyne over the ZnO/Cr2O3 Catalysts
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ZnO/Cr2O3 催化剂上 1,1,1,3,3-五氟丙烷选择性脱氟化氢合成四氟丙烯和三氟丙炔
DOI：
10.1002/slct.202002721
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发表时间：
2020
期刊：
影响因子：
2.1
通讯作者：
Luo Mengfei
中科院分区：
文献类型：
--
作者：
Jia Wenzhi;Fang Xiuxiu;Fang Chentao;Hu Caihong;Song Ji;ong;Luo Mengfei
采用浸渍法制备了一系列ZnO/Cr2 O3催化剂，考察了ZnO对1，1，1，3，3-五氟丙烷（CF 3CH 2CHF 2）选择性脱氢制异丙烯（CFH= CHCF 3，CH 2 = CFCF 3）和3，3，3-三氟丙炔（CH = CCF 3）的催化活性的促进作用。采用XRD、拉曼、BET、NH3-TPD和XPS等手段对ZnO/Cr2 O3催化剂进行了表征。随着Zn负载量的增加，Cr_2O_3的晶粒尺寸和催化剂的比表面积均增大。当ZnO的加入量为2mol%时，催化剂的表面酸性最高（1.02 μ mol g ~（-1））。ZnO/Cr_2O_3催化剂表面的Cr物种主要为Cr_2O_3、Cr（OH）_3和CrO_3。随着ZnO含量的增加，Cr2 O3的相对含量增加，而Cr（OH）3和CrO 3的相对含量减少。结果表明，ZnO负载量和反应温度对四种产物（E-CFH = CHCF 3，Z-CFH= CHCF 3，CH 2 = CFCF 3和CH = CCF 3）的选择性有较大影响。对于2 ZnO/Cr2 O3催化剂，E-和Z-CFH= CHCF 3的最低选择性分别为61.2%和15.7%，而CH 2 = CFCF 3和CH等价于CCF 3由于最高的表面酸性而在450 ℃下实现最高的选择性（分别为11.7%和9.8%）。
A series of ZnO/Cr2O3 catalysts were prepared by an impregnation method, and the promoted role of ZnO on the activity for selective dehydrofluorination of 1,1,1,3,3-pentafluoropropane (CF3CH2CHF2) to tetrafluoropropylene (CFH=CHCF3 and CH2=CFCF3) and 3,3,3-trifluoropropyne (CH equivalent to CCF3) was investigated. The ZnO/Cr2O3 catalysts were characterized by XRD, Raman, BET, NH3-TPD and XPS. As more Zn was loaded, both the crystallite size of the Cr2O3 and the surface area of catalysts both increased. The surface acidity of catalysts was the highest (1.02 mu mol g(-1)) when 2 mol % of ZnO was added. Surface Cr species on the surface of ZnO/Cr2O3 catalysts were identified, including Cr2O3, Cr(OH)(3) and CrO3. As the ZnO content increased, the relative content of Cr2O3 elevated, while the relative contents of Cr(OH)(3) and CrO3 decreased. It was found that the selectivities to four products (E-CFH=CHCF3, Z-CFH=CHCF3, CH2=CFCF3 and CH equivalent to CCF3) were greatly affected by the ZnO loading and reaction temperature. For the 2ZnO/Cr2O3 catalyst, the lowest selectivities to E- and Z-CFH=CHCF3 were 61.2 and 15.7 %, respectively, while CH2=CFCF3 and CH equivalent to CCF3 achieved the highest selectivity (11.7 % and 9.8 %, respectively) at 450 degrees C due to the highest surface acidity.