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

碳纳米管（CNTs）未能满足长期以来人们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具有“手性”（n,m）结构的单壁纳米管；尽管首席研究员在理论上争论说，如果催化剂、载体和化学气相沉积条件的适当组合能够实现，这种结构应该是可能的。最近，实验成功地证明了这种手性碳纳米管的制备。该项目将利用实验成果发展完善和扩展的理论预测，以指导催化化学气相沉积（CCVD）的进一步发展，以获得最佳的催化材料和加工条件。在工业规模上生产高纯度的单壁碳纳米管的能力可能对碳纳米管技术的商业应用产生深远的影响，理想情况下是由美国研究人员领导。该项目将发展PI小组最近的重大突破，揭示碳纳米管手性的起源可以通过一套指导方针来描述，这些指导方针将有助于设计（n,m）靶向碳纳米管合成的催化剂。研究人员现在清楚地认识到，这种复杂的现象位于两个大而成熟的领域的交叉点：多相催化和晶体生长。将化学和材料科学的这些范式结合在一起，有望形成一个变革性的理论框架，该框架应该能够找到设计手性选择性碳纳米管生产的方法，从而推进各种期待已久的应用，所有这些应用都有待于单一（n,m）类型材料的可用性。这将通过对各种金属-纳米颗粒催化剂的结构和能量学进行全面的原子研究，并结合对催化剂-碳纳米管界面上的统治过程的热力学和动力学进行最先进的定量分析来实现。为了更有可能获得重要的新理解，基于这种微观结果的假设将通过与文献中的实验数据的持续比较以及与几个实验实验室的联系来验证。该项目的跨学科性质将为研究生和本科生在计算化学、分子动力学和统计物理方面提供教育机会。研究成果将组织在一个策划的公共资料财产数据库中。该项目还包括通过莱斯大学向休斯敦高中生推广，并与休斯敦自然科学博物馆建立密切联系。

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.