论文部分内容阅读
以低廉的铜氨络合物(Cu-TEPA)为模板剂,通过原位水热合成法制备了Cu-SSZ-13。考察了两种铜盐和氢氧化钠用量对Cu-SSZ-13的晶相结构和形貌的影响,测试了两种铜盐制备的Cu-SSZ-13和金属改性的Cu-SSZ-13在甲醇制烯烃(MTO)中的催化性能。用XRF、XRD、SEM、N2等温吸附脱附(BET)和NH3程序升温脱附(NH3-TPD)对催化剂进行了表征。结果表明:碱度对Cu-SSZ-13的结晶度有很大影响,较高或较低的碱度会导致方沸石杂晶的产生,甚至生成纯相方沸石,n(Na2O)∶n(Al2O3)的较佳值为4.7~5;在MTO反应中,硝酸铜制备的CuSSZ-13的氢转移反应剧烈,反应初期丙烷选择性达到40%,远高于硫酸铜制备的Cu-SSZ-13的丙烷选择性(19%),因此,在抑制副反应发生上,Cu-SSZ-13/Cu SO4要优于Cu-SSZ-13/Cu(NO3)2。锰改性的Cu-SSZ-13明显提高了抗积炭失活能力,在反应温度440℃、质量空速(WHSV)5 h-1条件下,催化寿命从未改性的30 min延长到了65 min。
Cu-SSZ-13 was prepared by the in-situ hydrothermal method with Cu-TEPA as template. The effects of two kinds of copper salts and sodium hydroxide on the crystal structure and morphology of Cu-SSZ-13 were investigated. Cu-SSZ-13 and Cu-SSZ-13 Catalytic properties in methanol-to-olefins (MTO). The catalysts were characterized by XRD, XRD, SEM, N2 isothermal adsorption and desorption (BET) and NH3-TPD. The results show that alkalinity has a great effect on the crystallinity of Cu-SSZ-13. The higher or lower alkalinity leads to the generation of heteroporphyrin and even the formation of pure zeolite, n (Na2O): n ) Was 4.7 ~ 5. In the MTO reaction, the CuSSZ-13 prepared by Cu (NO3) 3 was more hydrogen transfer reaction, the propane selectivity was 40% in the initial stage of the reaction, which was much higher than that of Cu-SSZ-13 Propane selectivity (19%). Therefore, Cu-SSZ-13 / Cu SO4 is superior to Cu-SSZ-13 / Cu (NO3) 2 in inhibiting side reactions. Manganese-modified Cu-SSZ-13 markedly improved the anti-carbon deposition inactivation ability. Under the reaction temperature of 440 ℃ and mass hourly space velocity (WHSV) of 5 h-1, the catalytic life prolonged from 30 min min.