乙半化对Pd-Bi金属间化合物:一个DFT与微动力学建模研究结合
Bing-Bing Li1, Hong-Yan Ma1, Gui-Chang Wang2
1Tianjin RenAi College, Tianjin 301636, China.
将 (Bi) 添加到 (Pd) 催化剂中可以提高乙烯半化中的选择性和稳定性. 密度函数理论和微动力学建模揭示Bi改变电子性质,削弱中间吸附和提高乙烯选择性.
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
- 表面化学 表面化学
背景情况:
- 乙半化是至关重要的,但由于纯 (Pd) 催化剂的选择性和稳定性问题,具有挑战性.
- - (Pd-Bi) 双金属化合物表现出更好的催化性能和长期稳定性,但它们的反应机制仍然不清楚.
研究的目的:
- 阐明Pd(100),Pd3Bi1(100) 和Pd1Bi1(100) 表面上的乙半化机制.
- 了解 (Bi) 在改变催化剂活性和选择性方面的作用.
- 为了建立表面电子特性和催化结果之间的关系.
主要方法:
- 用密度函数理论 (DFT) 的计算来建模反应路径.
- 使用微动力学建模来模拟整体反应动力学.
- 进行了表面d频段中心 (εd) 计算,以分析电子效应.
主要成果:
- 石添加降低了表面的d波段中心 (εd),削弱了中间吸附强度.
- 在Pd-Bi合金上,由于缺乏连续的Pd表面位,因此阻碍了乙基 (CCH3) 的形成.
- 在Pd-Bi合金上,弱结合的乙烯有助于高选择性,尽管乙烯具有失活的固体效应.
结论:
- 这项研究确定了表面d带中心 (εd) 与乙半化中的催化剂活性/选择性之间的相关性.
- -合金为设计高度选择性和稳定的化催化剂提供了一个有希望的策略.
- 了解斯木的电子和硬质效应是未来催化剂设计的关键.
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