表面连接体长度影响了多氧酸氧化物集群中H原子吸收的动力学
Chari Y M Peter1, Eric Schreiber1, Kathryn R Proe1
1Department of Chemistry, University of Rochester, Rochester, NY 14627, USA. matson@chem.rochester.edu.
Dalton transactions (Cambridge, England : 2003)
|October 18, 2023
概括
在氧化瓦纳集群上的氧化物连接体的长度不会影响原子转移热力学,但会显著影响反应动力学. 较短的甲氧化物配体加快了反应.
科学领域:
- 材料科学 材料科学 材料科学
- 无机化学 无机化学
- 催化剂是一种催化剂.
背景情况:
- 氧化金属表面的原子 (H-原子) 吸收对于催化和能量储存至关重要.
- 了解控制H原子转移热力学和动力学的因素是具有挑战性的.
- 聚氧化-氧化物 (POV-氧化物) 集群为研究表面H原子相互作用提供了一个模型系统.
研究的目的:
- 为了研究表面氧化物连接体长度如何影响氧原子 (O原子) 缺陷形成通过H原子转移在氧化瓦纳集群.
- 阐明不同氧化物链长度对质子合电子转移 (PCET) 反应的热力学和动力学影响.
主要方法:
- 低价值的多氧化酸-氧化集群的合成和特征与不同的氧化链长度 (R = Me, Et, Pr, Bu).
- 对这些集群的H原子转移反应的实验分析.
- 对PCET过程的动力学和热力学评估.
主要成果:
- 氧化联体长度并没有显著改变H原子转移的热力学.
- 反应动力学在很大程度上取决于联体长度,甲氧化联体 ([V6O7(OMe) [12]1-) 显示了约20倍更快的反应速率.
- 增加超出乙烯的阿利法链长度并没有进一步改变反应速率,这表明固体或溶剂兼容性影响.
结论:
- 表面连接体长度是控制POV-氧化物集群中H原子转移的动力学 (但不是热力学) 的关键因素.
- 甲氧化物桥梁集群表现出显著增强的反应性,突出显示了连接体设计在调整催化活性方面的潜力.
- 固体阻碍和溶剂相互作用可能在较长的氧化物链的反应速度中缓和起作用.
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