为什么一个简单的vanadate是低效的催化剂在氧化与H的
Maxim L Kuznetsov1, Armando J L Pombeiro1
1Centro de Química Estrutural, Institute of Molecular Sciences, Departamento de Engenharia Química, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal. max@mail.ist.utl.pt.
Dalton transactions (Cambridge, England : 2003)
|June 7, 2023
概括
简单的瓦纳酸盐在与过氧化的氧化过程中是不活跃的. 新的DFT计算揭示了产生氧化基的新,高效的机制,以及消耗它们的竞争途径,解释了观察到的不活性.
科学领域:
- 无机化学 无机化学 有机化学
- 催化剂是一种催化剂.
- 计算化学计算化学
背景情况:
- (V) 复合物通常是使用过氧化氧化氧化的活性催化剂.
- 然而,简单的酸盐在中性介质中表现出不活性,这种现象不能完全解释为过氧化激活不足.
研究的目的:
- 通过使用DFT计算来研究由简单的瓦纳达和过氧化氧化氧化的机制.
- 为了阐明在这种催化系统中观察到的简单瓦纳达的不活性背后的原因.
主要方法:
- 用密度函数理论 (DFT) 的计算来研究反应机制和激活障碍.
- 该研究的重点是产生活性氧化物种和潜在的副作用.
主要成果:
- 通过在特定的瓦纳达中间体中通过同质的O-O键裂变产生基基 (HO ̇) 的新型机制被确定,与芬顿样途径相比,其激活屏障明显较低 (15.4 kcal mol-1).
- 在中间体中存在非无害的OO配体,有助于这种高效的基因生成.
- 发现了一种竞争的H2O2变异通路,其中产生的HȮ激素被原子迅速消耗,导致分子氧气消除和催化活性降低.
结论:
- 简单的vanadates在氧化中的不活性归因于一种高效的新型基因生成途径和快速的基因清理副作用反应的组合.
- 这项研究修订了对酸盐介导的H2O2激活的理解,并强调了考虑催化系统中竞争性途径的重要性.
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