更多的碳沉积是否必然导致更差的催化性能?
1Institute for New Energy Materials and Low Carbon Technologies, School of Materials Science and Engineering, Tianjin University of Technology, Tianjin 300384, China. wanghui2020@email.tjut.edu.cn.
概括
在甲改造过程中碳的积累较高并不总是降低催化剂活性. 动态碳迁移可以保持催化功能,即使有显著的焦炭形成,挑战传统智慧.
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
- 化学工程是化学工程的重要组成部分.
背景情况:
- 传统的理解将增加的碳沉积与减少的催化活性联系在一起.
- 高性能催化剂尽管发生了严重的焦炭封装,但仍表现出活性,这表明了复杂的关系.
研究的目的:
- 调查碳积累和甲干重制中的催化活性之间的关系.
- 为了确定增加的碳沉积是否不可避免地损害了催化性能,使用Ni/CexZr1-xO2催化剂.
主要方法:
- 利用甲的干式改制作为一个模型系统.
- 采用Ni/CexZr1-xO2 (0 ≤ x ≤ 1) 催化剂,其-的组成不同.
- 分析了焦炭沉积及其与催化活性的相关性.
主要成果:
- 最活跃的催化剂 (0.6Ni/CeO2) 产生了最多的焦炭,形成了覆盖整个表面的石墨碳.
- 最不活跃的催化剂 (0.6Ni/ZrO2) 显示由于初始被动化而导致的焦炭积累最小.
- 尽管有大量的焦炭,但催化活性仍然存在,如果碳动态迁移,则会重新暴露活性部位.
结论:
- 碳积累并不总是导致催化活性下降.
- 远离活性位点的动态碳迁移可以保持催化功能.
- 这一发现挑战了对焦炭沉积的传统观点,认为焦炭沉积对催化剂性能是有害的.
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