氧化物中的地下氧物种可以参与催化反应吗? 一个17O固态核磁共振研究
Changju Yang1, Jia Wang2, Xiaoli Xia1
1Key Laboratory of Mesoscopic Chemistry of Ministry of Education and Collaborative Innovation Center of Chemistry for Life Sciences, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.
The journal of physical chemistry letters
|August 5, 2024
概括
氧化 (CeO2) 纳米棒中的地表氧离子在一氧化碳 (CO) 氧化反应中起着至关重要的作用. 这项研究表明,固态核磁共振 (NMR) 光谱如何区分和量化这些地下物种,推动催化研究.
科学领域:
- 材料科学 材料科学 材料科学
- 催化剂是一种催化剂.
- 表面化学 表面化学
背景情况:
- 从表面和散装物种区分地下催化剂物种是具有挑战性的,因为有限的表征方法.
- 了解地下物种的作用对于优化催化反应过程至关重要.
- 氧化 (CeO2) 是一个被广泛研究的催化剂,但其地下氧的确切作用仍在争论中.
研究的目的:
- 研究氧化 (CeO2) 纳米棒中地下氧物种对一氧化碳 (CO) 氧化反应的影响.
- 使用17O固态核磁共振 (NMR) 光谱学来区分表面和地下氧离子.
- 为了阐明在CO氧化过程中涉及地下氧的反应机制.
主要方法:
- 利用17O固态核磁共振 (NMR) 光谱来描述CeO2 (111) 纳米棒中的氧物种.
- 将CO引入CeO2纳米棒,并监测NMR信号强度的变化.
- 执行密度函数理论 (DFT) 计算以建模反应机制.
主要成果:
- 17O NMR光谱学成功地区分了CeO2纳米棒中的表面和地下氧离子.
- 引入CO导致表面和地下氧的NMR信号强度下降,对地下氧的影响更为明显.
- DFT的计算表明,在二氧化碳氧化过程中,地下氧离子迁移到填补表面氧空缺.
结论:
- 在CeO2纳米棒中的地下氧物种积极参与CO氧化反应.
- 反应机制涉及地下氧气补充表面氧气空缺.
- 开发的NMR方法为在异质催化中研究地下物种提供了一种新方法,并且可以扩展到其他反应.
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