This study was aimed to investigate the effects of hydrothermal aging, propene and SO<sub>2</sub> poisoning on the ammonia-selective catalytic reduction (NH<sub>3</sub>-SCR) performance of both...This study was aimed to investigate the effects of hydrothermal aging, propene and SO<sub>2</sub> poisoning on the ammonia-selective catalytic reduction (NH<sub>3</sub>-SCR) performance of both Cu-SAPO-34 and Cu-ZSM-5. The catalytic activities of fresh, aged and poisoned samples were tested in ammonia-selective catalytic reduction (NH<sub>3</sub>-SCR) of NO<sub>x</sub> conditions. The XRD, TG and N<sub>2</sub>-desorption results showed that the structures of the Cu-SAPO-34 and Cu-ZSM-5 remained intact after 750˚C hydrothermally aged, SO<sub>2</sub> and propene poisoned. After hydrothermal aging at 750˚C for 12 h, the NO reduction performance of Cu-ZSM-5 was significantly reduced at lower temperatures, while that of Cu-SAPO-34 was less affected. Moreover, Cu-SAPO-34 catalyst showed high NO conversion with SO<sub>2</sub> or propene compared to Cu-ZSM-5. However, Cu-ZSM-5 showed a larger drop in catalytic activity with SO<sub>2</sub> or propene compared to Cu-SAPO-34 catalyst. The H<sub>2</sub>-TPR results showed that Cu<sup>2 </sup> ions could be reduced to Cu<sup> </sup> and Cu<sup>0</sup> for Cu-ZSM-5, while no significant transformation of copper species was observed for Cu-SAPO-34. Meanwhile, the UV-vis DRS results showed that CuO species were formed in Cu-ZSM-5, while little changes were observed for the Cu-SAPO-34. Cu-SAPO-34 showed high sulfur and hydrocarbon poison resistance compared to Cu-ZSM-5. In summary, Cu-SAPO-34 with small-pore zeolite showed higher hydrothermal stability and better hydrocarbon and sulfur poison resistant than Cu-ZSM-5 with medium-pore.展开更多
综述了生物质甲醇/二甲醚制烯烃(methanol to olefins/dimethyl ether to olefins,MTO/DTO)中发挥催化作用的分子筛的种类及性能特点,对ZSM-5分子筛和SAPO-34分子筛的合成方法和改性方法进行了阐述,重点分析了水热合成法、无模板剂合成...综述了生物质甲醇/二甲醚制烯烃(methanol to olefins/dimethyl ether to olefins,MTO/DTO)中发挥催化作用的分子筛的种类及性能特点,对ZSM-5分子筛和SAPO-34分子筛的合成方法和改性方法进行了阐述,重点分析了水热合成法、无模板剂合成法、微波合成法、干凝胶合成法、无溶剂合成法、离子热合成法和超声波合成法等合成方法,以及改变硅铝比、金属改性、非金属改性、碱改性、水热处理改性、酸改性、氨基化改性和氟化物处理改性等改性方法。目前,分子筛的合成方法和改性方法对分子筛性能的调控仍有不足,而分子筛的性能与其结构及酸性密切相关。调控分子筛的结构及酸性,可以进一步提升分子筛的催化性能与合成效率,延长分子筛的催化寿命,降低甲醇/二甲醚生产的工艺成本,减少对环境的危害。展开更多
基金supported by the National Basic Research Program of China (2010CB732303)the National Natural Science Foundation of China (21173174, 20923004, 21033006, and 21161130522)the Program for Changjiang Scholars and Innovative Research Team in University (IRT1036)~~
文摘This study was aimed to investigate the effects of hydrothermal aging, propene and SO<sub>2</sub> poisoning on the ammonia-selective catalytic reduction (NH<sub>3</sub>-SCR) performance of both Cu-SAPO-34 and Cu-ZSM-5. The catalytic activities of fresh, aged and poisoned samples were tested in ammonia-selective catalytic reduction (NH<sub>3</sub>-SCR) of NO<sub>x</sub> conditions. The XRD, TG and N<sub>2</sub>-desorption results showed that the structures of the Cu-SAPO-34 and Cu-ZSM-5 remained intact after 750˚C hydrothermally aged, SO<sub>2</sub> and propene poisoned. After hydrothermal aging at 750˚C for 12 h, the NO reduction performance of Cu-ZSM-5 was significantly reduced at lower temperatures, while that of Cu-SAPO-34 was less affected. Moreover, Cu-SAPO-34 catalyst showed high NO conversion with SO<sub>2</sub> or propene compared to Cu-ZSM-5. However, Cu-ZSM-5 showed a larger drop in catalytic activity with SO<sub>2</sub> or propene compared to Cu-SAPO-34 catalyst. The H<sub>2</sub>-TPR results showed that Cu<sup>2 </sup> ions could be reduced to Cu<sup> </sup> and Cu<sup>0</sup> for Cu-ZSM-5, while no significant transformation of copper species was observed for Cu-SAPO-34. Meanwhile, the UV-vis DRS results showed that CuO species were formed in Cu-ZSM-5, while little changes were observed for the Cu-SAPO-34. Cu-SAPO-34 showed high sulfur and hydrocarbon poison resistance compared to Cu-ZSM-5. In summary, Cu-SAPO-34 with small-pore zeolite showed higher hydrothermal stability and better hydrocarbon and sulfur poison resistant than Cu-ZSM-5 with medium-pore.
文摘综述了生物质甲醇/二甲醚制烯烃(methanol to olefins/dimethyl ether to olefins,MTO/DTO)中发挥催化作用的分子筛的种类及性能特点,对ZSM-5分子筛和SAPO-34分子筛的合成方法和改性方法进行了阐述,重点分析了水热合成法、无模板剂合成法、微波合成法、干凝胶合成法、无溶剂合成法、离子热合成法和超声波合成法等合成方法,以及改变硅铝比、金属改性、非金属改性、碱改性、水热处理改性、酸改性、氨基化改性和氟化物处理改性等改性方法。目前,分子筛的合成方法和改性方法对分子筛性能的调控仍有不足,而分子筛的性能与其结构及酸性密切相关。调控分子筛的结构及酸性,可以进一步提升分子筛的催化性能与合成效率,延长分子筛的催化寿命,降低甲醇/二甲醚生产的工艺成本,减少对环境的危害。
