arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0909.0545cond-mat.mtrl-sci
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氮化硼纳米管合成的计算研究:催化剂形态如何稳定氮化硼键

Computational study of boron nitride nanotube synthesis: how catalyst morphology stabilizes the boron nitride bond

S. Riikonen, A. S. Foster, A. V. Krasheninnikov, R. M. Nieminen

摘要:

为了理解为什么氮化硼纳米管生长的催化方法比碳纳米管差得多,我们使用第一性原理计算来研究在铁催化剂上形成N2,B2和BN分子的元素反应的能量学。我们观察到,在这些小分子的情况下,催化活性受到铁表面上B2形成的阻碍。我们还观察到,我们的纳米颗粒模型中存在的台阶边缘的局部形态使氮化硼分子相对于B2稳定,这是由于台阶边缘同时为氮和硼提供具有不同配位的位点的能力。我们的研究结果强调了高产量的BN纳米管的化学气相沉积生长的原子步骤的重要性,并可能勾勒出提高效率的方法的新方向。

英文摘要:

In an attempt to understand why catalytic methods for the growth of boron nitride nanotubes work much worse than for their carbon counterparts, we use first-principles calculations to study the energetics of elemental reactions forming N2, B2 and BN molecules on an iron catalyst. We observe that in the case of these small molecules, the catalytic activity is hindered by the formation of B2 on the iron surface. We also observe that the local morphology of a step edge present in our nanoparticle model stabilizes the boron nitride molecule with respect to B2 due to the ability of the step edge to offer sites with different coordination simultaneously for nitrogen and boron. Our results emphasize the importance of atomic steps for a high yield chemical vapor deposition growth of BN nanotubes and may outline new directions for improving the efficiency of the method.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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