弥合实验和理论之间的尺寸差距:大规模的DFT计算在现实尺寸的Pd颗粒上进行乙烯化化
Apostolos Kordatos1, Khaled Mohammed1, Reza Vakili2
1School of Chemistry and Chemical Engineering, University of Southampton UK c.skylaris@soton.ac.uk.
RSC advances
|September 3, 2024
概括
密度函数理论 (DFT) 的计算现在模拟了更大的金属纳米粒子,揭示了影响催化性能的电子差异. 这为实际应用推进了计算催化剂.
科学领域:
- 不同质的催化剂.
- 计算材料科学 计算材料科学
- 表面科学是一门科学.
背景情况:
- 金属纳米粒子在异质催化中至关重要,尺寸影响性能.
- 密度函数理论 (DFT) 用于研究纳米粒子属性,但在计算上仅限于小集群.
- 弥合小型模拟集群和更大,实际上相关的纳米粒子之间的差距至关重要.
研究的目的:
- 通过使用DFT,研究大型 (Pd) 和碳化物 (PdC) 纳米粒子的电子和化学特性.
- 为了评估DFT对超出典型的50原子极限的纳米粒子的准确性.
- 探索纳米粒子尺寸和碳合并对催化活性的影响.
主要方法:
- 在大型金属纳米粒子上使用ONETEP代码进行高效的DFT计算.
- 在超过300个原子的Pd和PdC纳米粒子上进行了计算 (大约. 它的直径为2.5纳米).
- 计算了C2H2,C2H4和C2H6的吸附能量,以及化反应的反应能量.
主要成果:
- 在大 (∼300个原子) 和小的Pd/PdC纳米粒子之间观察到电子结构的显著差异.
- 在较大的纳米粒子上,碳化合物的吸附能量显著更高.
- 在PdC纳米粒子中加入碳减弱了碳化合物吸附,并阻碍了乙烯化成乙.
结论:
- 在大型纳米粒子 (∼300个原子) 上进行的DFT模拟提供了在较小集群中看不到的关键见解.
- 大约5%的碳和2.5纳米直径的PdC纳米粒子显示出作为活性化催化剂的潜力.
- 这项工作使得DFT可以应用于实验相关的纳米粒子大小,增强催化研究.
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