从气到乙烯的动态演变,通过摩登石转化为合成气:从碳化合物池到碳化路径的过渡
1State Key Laboratory of Petroleum Molecular & Process Engineering, Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200062, China.
Journal of the American Chemical Society
|June 16, 2025
概括
焦炭沉积在摩登石 (MOR) 岩孔中动态地改变合成气转换路径. 这种演变通过随着时间的推移改变反应路径,使乙烯的选择性从14.3%提高到80%.
科学领域:
- 催化剂
- 材料科学
- 化学工程
背景情况:
- 了解双功能催化剂的反应中间演变是控制合成气转化产品的关键.
- 氧化物-化物 (OX-ZEO) 系统为合成气转化提供可调节的催化性能.
研究的目的:
- 在ZnAlOx-mordenite (MOR) 双功能催化剂的合成气转化过程中研究反应中间体的拓依赖演化.
- 阐明现场焦炭沉积在产品选择性转变中的作用.
主要方法:
- 在ZnAlOx-MOR中合成气转换过程中产品分布的时间解析分析.
- 产品选择性的变化与焦炭沉积程度和孔隙可访问性的相关性.
主要成果:
- 随着时间的推移,乙烯的选择性从14.3%增加到80%,而的选择性则从46.9%降低到0.3%.
- 在现场的焦炭沉积主要阻塞了12环孔,将反应途径从甲醇到 (MTP) 转移到8环孔的碳化路径.
- 焦炭改性催化剂实现了高乙烯选择性 (80%) 和稳定的乙烯/比为12.7.
结论:
- 在MOR二氧化的12环孔中的现场焦炭沉积有效地增加了合成气转化过程中的乙烯产量.
- 通过焦炭沉积控制分子扩散和孔径可达性是调整OX-ZEO催化剂产品分布的可行策略.
- 对12环酸位点进行选择性失活是不必要的,以增强乙烯的产生.
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