Catalytic Reactivity and Surface Interactions During Early Stages of Single-Walled Carbon Nanotube Formation
Abstract
Critical elements in the controlled production of single-walled carbon nanotubes
(SWCNTs) methods include the substrate, the catalyst metal particle, and the carbon
precursor gas feed. This research targets some of the unanswered questions and hidden
relations between the components of the nanotube-particle-substrate system. Highly
accurate molecular simulations, along with new experimental observations and the use
of high-resolution transmission electron microscopy (HRTEM), have opened the door
for a deeper understanding of nanotube formation mechanisms. This dissertation
proposes a new theoretical model to explain the intrinsic tube-particle diameter relation
and its applicability in various experimental setups. Additionally, new work presented
here explains distinct scenarios that may break the tube-particle correlation and shows
oxygen as an SWCNT nucleation promoter. Finally, we expose the effect of composition
fluctuations on cobalt catalyst particles reactivy using the meta-stable cobalt carbide
phases. We observed that the structure-evolving catalyst particle during carbon
deposition is a unique environment far from equilibrium where surface reactions and
diffusion kinetics may quickly move the scale between inactive and active surfaces.
Subject
Single-Walled Carbon Nanotube (SWCNT)Nucleation
Surface Reactivity
Diameter Control
Interfacial Interactions
DFT Calculations
Molecular modeling
Citation
Carvajal Diaz, Mauricio (2021). Catalytic Reactivity and Surface Interactions During Early Stages of Single-Walled Carbon Nanotube Formation. Doctoral dissertation, Texas A&M University. Available electronically from https : / /hdl .handle .net /1969 .1 /196389.