| 田密,高平,张荣慧,王来来,周旺鹰,谢文健.改性三氧化二铬催化1,1,3,3-四氯丙烯氟化高选择性合成反式-1-氯-3,3,3-三氟丙烯研究[J].分子催化,2020,34(1):45-57 |
| 改性三氧化二铬催化1,1,3,3-四氯丙烯氟化高选择性合成反式-1-氯-3,3,3-三氟丙烯研究 |
| Highly Selective Synthesis of Trans-1-Chloro-3,3,3-Trifluoropropene by the Vapor Fluorination of 1,1,3,3-Tetrachloropropene with HF over the Chromium Oxide-Based Catalysts |
| 投稿时间：2019-11-17 修订日期：2019-12-12 |
| DOI： |
| 中文关键词: 氟化 1,1,3,3-四氯丙烯 氟化氢 反式-1-氯-3,3,3-三氟丙烯 氟化三氧化二铬 |
| 英文关键词:fluorination 1,1,3,3-Tetrachloropropene HF trans-1-chloro-3,3,3-trifluoropropene fluorinated chromia |
| 基金项目:Key Research Program of Science and Technology Project of Gansu province (No.18YF1GA124). |
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| 中文摘要: |
| 反式-1-氯-3，3，3-三氟丙烯（HCFO-1233zd（E））是近年来正在研发的第4代发泡剂，其大气臭氧消耗潜能值为0.000 24，温室效应潜能值为7.0，毒性低，常态下不燃，使用安全；它也是合成含氟精细化工品的中间体，以及合成氟树脂和氟弹性体的单体.我们制备了Al，Zn，Co改性的Cr2O3催化剂，将其成功应用于1，1，3，3-四氯丙烯（HCC-1230za）与氟化氢反应中，高选择性地合成HCFO-1233zd（E），复合催化剂Zn/Cr2O3显示高稳定性，其中HCC-1230za转化率高达99.4%，HCFO-1233zd（E）的选择性高达98.2%.反应条件诸如反应物HF/HCC-1230za的摩尔比和反应温度等对产物分布有显著影响.在相对较低的温度（200℃）和较大的HF/HCC-1230za摩尔比（10∶1）下，对HCFO-1233zd（E）的选择性有利.通过XRD，XPS，BET和V70吡啶吸附红外光谱技术对复合催化剂Zn/Cr2O3进行了表征.XRD结果表明，催化剂中大多数无定形Cr2O3和高度分散微晶相Cr2O3共同导致催化剂的高活性和高稳定性.HCC-1230za的转化率与预氟化处理催化剂Zn/Cr2O3的比表面积有关，催化剂的比表面积越高，催化活性越高.XPS光谱表明，在预氟化过程中，表面铬氧化物可能与F原子强烈相互作用，从而导致Cr原子的化学环境发生广泛变化.V70吡啶吸附红外光谱和氨-程序升温脱附技术结果证明尚未失活的催化剂Lewis酸和Brønsted酸中心的数目和强度与新制备的催化剂相比明显提高. |
| 英文摘要: |
| Vapor fluorination of 1,1,3,3-tetrachloropropene (HCC-1230za) with HF to trans-1-chloro-3,3,3-trifluoropropene (HCFO-1233zd(E)) was investigated using the fluorinated Cr2O3 catalysts modified by Al3+, Zn2+, and Co2+. A highly active, selective, and long lifespan Zn/Cr2O3 catalyst was achieved for the first time, where 99.4% HCC-1230za conversion and 98.2% HCFO-1233zd (E) selectivity were obtained, and the selectivity to HCFO-1233zd (E) was favored at 200 ℃ and HF/HCC-1230za molar ratio (10:1). The catalysts were characterized by XRD, XPS, BET, V70 pyridine adsorption infrared spectrometer and NH3-TPD techniques. The XRD results of catalysts Zn/Cr2O3 indicate that most of the amorphous chromium oxide and finely dispersed microcrystalline phase of Cr2O3 together lead to high activity and long lifespan. The conversion of HCC-1230za and the selectivity to HCFO-1233zd (E) are related to the specific surface area of the fluorinated catalyst, and the higher the specific surface area of the catalyst, the higher selectivity. The XPS spectra of catalyst Zn/Cr2O3 show that exterior Cr2O3 after 118 h reaction formed CrOxFy species. The number and strength of Lewis and Brønsted acid sites for Zn/Cr2O3 catalysts after 118 h reaction is significantly increased than the fresh one. |
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