| 引用本文: | 潘淑倩,余金鹏,徐华胜,周永贤,张丽,王鹏飞. 前驱试剂对铬系催化剂丙烷脱氢反应的影响[J]. 石油与天然气化工, 2020, 49(4): 48-55. |
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| 前驱试剂对铬系催化剂丙烷脱氢反应的影响 |
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潘淑倩1,余金鹏1,2,3,4,徐华胜1,2,3,4,周永贤1,2,3,4,张丽2,王鹏飞1,2,3,4
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1.上海化工研究院有限公司;2.上海绿强新材料有限公司 ;3.聚烯烃催化技术与高性能材料国家重点实验室;4.上海市聚烯烃催化技术重点实验室
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| 摘要: |
| 分别以硝酸铬、三氧化铬、重铬酸钙和重铬酸钾为前驱试剂,制备了丙烷脱氢铬系催化剂,催化剂中Cr名义负载量(w)均为11%,在质量空速0.7 h-1、反应温度600 ℃的条件下,考察了催化剂的丙烷脱氢活性。通过XRD、SEM、NH3-TPD、H2-TPR、UV-vis等方法对不同铬前驱试剂合成催化剂的晶体结构、表面形貌、表面酸性、表面还原性、Cr元素价态进行表征；利用固定床微型反应装置测定了催化剂的丙烷脱氢反应活性；借助高频红外碳硫仪、热裂解GC-MS和原位红外等手段对反应后催化剂积炭量、积炭种类、反应中间产物进行分析。结果 表明:以硝酸铬、三氧化铬为前驱试剂的催化剂Cr(III)-RC、Cr(VI)-RC表面以弱酸位点为主,高价铬(Cr6+)易被还原,丙烷转化率与丙烯选择性较高。以重铬酸钙、重铬酸钾为前驱试剂的催化剂Cr(VI)-Ca-RC、Cr(VI)-K-RC表面以中强酸位点为主,高价铬(Cr6+)不易被还原,积炭副反应较强,丙烷转化率与丙烯选择性较低。合理调节催化剂表面酸性,促进高价铬(Cr6+)的还原,将有利于制备高性能铬系丙烷脱氢催化剂。 |
| 关键词: 丙烷脱氢 复合载体 铬氧化物催化剂 |
| DOI：10.3969/j.issn.1007-3426.2020.04.009 |
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| 基金项目:上海市工业强基专项“半导体行业用高纯氧化铝造粒料的智能化制备及产业化”(GYQJ-20118-1-22) |
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| Effect of precursor nature on propane dehydrogenation of chromium catalyst |
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Pan Shuqian1, Yu Jinpeng1,2,3,4, Xu Huasheng1,2,3,4, Zhou Yongxian1,2,3,4, Zhang Li2, Wang Pengfei1,2,3,4
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1. Shanghai Research Institute of Chemical Industry Co., Ltd., Shanghai, China;2. Shanghai Lüqiang New Materials Co., Ltd., Shanghai, China;3. State Key Laboratory of Polyolefins and Catalysis, Shanghai, China;4. Shanghai Key Laboratory of Catalysis Technology for Polyolefins, Shanghai, China
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| Abstract: |
| Using chromium nitrate, chromium (VI) oxide, calcium dichromate trihydrate or potassium dichromate as precursors, chromium catalysts for propane dehydrogenation are prepared. The nominal chromium loading in the catalyst is 11 wt%. The propane dehydrogenation activity of the catalyst is investigated under the conditions of weight hourly space velocity (WHSV) of 0.7 h-1 and reaction temperature of 600 ℃. XRD, SEM, NH3-TPD, H2-TPR and UV-vis are used to characterize the crystal structure, surface topography, surface acidity, surface reducibility, and chromium valence of different precursors catalysts. The propane dehydrogenation activity of the catalyst is measured with a fixed-bed miniature reaction device. The high-frequency infrared carbon-sulfur analyzer, thermal cracking GC-MS, and in-situ DRIFTS are used to analyze the amount of coke deposited, the type of coke deposited, and the reaction intermediates. The results show that the catalyst Cr (III)-RC with chromium nitrate or Cr (VI)-RC with chromium (VI) oxide as precursor have mainly weak acid sites on the surface, and its high-valent chromium (Cr6+) is easily reduced, the propane conversion and propylene selectivity are higher. The catalyst Cr(VI)-Ca-RC with calcium dichromate trihydrate or Cr(VI)-K-RC with potassium dichromate as precursor have mainly medium-strength acid sites on the surface, and its high-valent chromium (Cr6+) is not easily reduced, the side reactions are strong, and the propane conversion and propylene selectivity are lower. Adjusting the surface acidity of the catalyst reasonably and promoting the reduction of high-valent chromium (Cr6+) will be beneficial to the preparation of high-performance chromium-based propane dehydrogenation catalysts. |
| Key words: propane dehydrogenation composite support chromium oxide catalyst |
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