通过Pr-ion修饰改善富含Al的Cu-SSZ-13热的热水稳定性
Mengyang Chen1, Wenru Zhao2, Yingzhen Wei3
1School of Pharmaceutical and Chemical Engineering, Taizhou University Taizhou 318000 P. R. China hdmtzc@126.com.
Chemical science
|April 19, 2024
概括
将Pr-ion添加到富含的铜SSZ-13 (Cu-SSZ-13) 催化剂中,可以显著提高它们在水蒸气存在时的稳定性. 这种增强对于氨辅助选择性催化还原 (NH3-SCR) 应用至关重要.
科学领域:
- 催化剂是一种催化剂.
- 材料科学 材料科学 材料科学
- 犹太复国主义者是犹太复国主义者
背景情况:
- 富含的Cu-SSZ-13是氨辅助选择性催化还原 (NH3-SCR) 的潜在催化剂.
- 低水热稳定性阻碍了在潮湿条件下应用富含Al的热石.
- 商用Cu-SSZ-13的Si/Al比率 (10-12) 比Al丰富的变种 (4-6) 高.
研究的目的:
- 为了提高富含的Cu-SSZ-13催化剂的热水稳定性.
- 为了研究Pr-ion修饰对催化剂性能和稳定性的影响.
- 了解改善水热稳定性背后的机制.
主要方法:
- 合成Pr-离子修饰的Cu-SSZ-13催化剂.
- 高温水热老化 (HTA) 模拟恶劣的条件.
- 包括X射线衍射,瑞特维尔德精细化和电子偏磁共振 (EPR) 在内的表征技术.
- 密度函数理论 (DFT) 计算以阐明机制.
主要成果:
- 最佳 Pr 含量 (1.2 wt%) 在 HTA 后显著改善了热水稳定性.
- 与未经修改的Cu-SSZ-13-HTA.相比,CuPr1.2-SSZ-13-HTA显示出更好的NO转换窗口 (T80:225-550°C,T90:250-350°C).
- 位于8个环 (8MRs) 中的离子在老化过程中抑制了不活性CuO的形成.
- 过度的P 离子导致CuO的形成,并降低了催化性能.
结论:
- 离子修饰是一种有效的策略,可以提高Al-丰富的Cu-SSZ-13催化剂的热水稳定性.
- 改善的稳定性归因于防止CuO形成的Pr离子.
- 这项工作为开发NH3-SCR的强大的热酸催化剂提供了一个有前途的途径.
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