Catalyst design for (n,m)-targeted carbon nanotube syntheses

碳纳米管（CNT）未能满足人们长期以来对高表面积和出色电子性能的期望。 这主要是由于无法催化合成的纳米管作为单壁实体在一个图案化的“手性”（n，m）-结构;尽管理论上的论点，由主要研究者，这种结构应该是可能的，如果催化剂，支持和化学气相沉积条件的适当组合可以实现。 最近，在生产这种手性碳纳米管的实验成功已被证明。 该项目将利用实验成果来开发改进和扩展的理论预测，以指导催化化学气相沉积（CCVD）朝着最佳催化材料和工艺条件的进一步发展。 以工业规模生产高纯度单壁碳纳米管的能力可能对CNT技术的商业应用产生深远影响，理想情况下，美国研究人员将引领这一方向。该项目将发展PI小组最近的一项关键突破，揭示CNT手性的起源可以通过一套指导方针来描述，这将有助于设计（n，m）靶向CNT合成的催化剂。研究人员现在清楚地认识到，这种复杂的现象存在于两个大而成熟的领域的交叉点：多相催化和晶体生长。将这些来自化学和材料科学的范例汇集在一起，预计将产生一个变革性的理论框架，该框架应能够找到设计手性选择性CNT生产的方法，从而推进各种期待已久的应用，所有这些都有待于单一（n，m）型材料的可用性。这将通过对各种金属纳米颗粒催化剂的结构和能量进行全面的原子学研究，并结合对催化剂-CNT界面处的裁决过程的热力学和动力学进行最先进的定量分析来实现。为了使更高的概率显着的新的理解，假设的基础上，这种微观结果将验证通过持续比较与文献中的实验数据，并通过与几个实验室的联系。 该项目的跨学科性质将为计算化学，分子动力学和统计物理学的研究生和本科生提供教育机会。 研究结果将被组织在一个策划的公共材料财产数据库。 该项目还将通过赖斯大学和休斯顿自然科学博物馆的密切联系，向休斯顿高中生进行宣传。

Carbon nanotubes (CNTs) have failed to fulfill long-held expectations of high-surface-area coupled with outstanding electronic properties. This owes primarily to an inability to catalytically synthesize the nanotubes as single-walled entities in a patterned "chiral" (n,m)-structure; and is despite theoretical arguments by the principal investigator that such structures should be possible if the proper combination of catalyst, support and chemical vapor deposition conditions can be achieved. Recently, experimental success in producing such chiral CNTs has been demonstrated. The project will draw upon the experimental achievement to develop refined and expanded theoretical predictions that should guide further developments of catalytic chemical vapor deposition (CCVD) toward optimal catalytic materials and processing conditions. The ability to produce single-wall carbon nanotubes of high purity at industrial scale could have profound effects on commercial applications of CNT technology, ideally with U.S. researchers leading the way.The project will evolve a critical recent breakthrough in the PI's group revealing that the origin of CNT chirality can be described by a set of guidelines that will aid design of catalysts for (n,m)-targeted CNT synthesis. The researchers now clearly recognize that this complex phenomenon lies at the intersection of two large and mature fields: heterogeneous catalysis and crystal growth. Bringing together these paradigms from chemistry and materials science is expected to result in a transformative theoretical framework that should enable finding ways to engineer chiral selective CNT production, thus advancing a variety of long-awaited applications, all pending availability of single (n,m) type material. This will be achieved by a comprehensive atomistic investigation of structure and energetics of various metal-nanoparticle catalysts combined with state-of-the-art quantitative analysis of the thermodynamics and kinetics of ruling processes at the catalyst-CNT interface. To enable a higher probability of significantly new understanding, hypotheses based on such microscopic results will be validated through a continuing comparison with experimental data in the literature and through contacts with several experimental labs. The cross-disciplinary nature of the project will provide educational opportunities to both graduate and undergraduate students in computational chemistry, molecular dynamics, and statistical physics. Research results will be organized in a curated public materials property database. The project will also involve outreach to Houston high school students through Rice University and close ties to the Houston Museum of Natural Sciences.