Carbon nanotubes (CNTs) have the potential to impact a number of next-generation technologies owing to their extraordinary electrical, thermal and chemical properties. The key to achieving their promise lies in maximizing their yield during synthesis, while at the same time tailoring their structural properties for their intended application. A number of approaches have been employed for increasing CNT yield, including the addition of growth promoters, feedstock compositional control, and improved catalyst design. Among all of the synthesis process variables, the growth temperature has arguably the greatest effect on growth behavior; an increase in the growth temperature enhances yield but also results in other issues such as amorphous carbon deposition (sooting), increasing tube diameters and excessive catalyst particle coarsening (Ostwald ripening and coalescence). The temperature is typically treated as a static variable, where a substrate coated with a metal catalyst film is heated in a hot-or cold-wall furnace up to a predetermined value, followed by a hold time at that temperature while the catalyst is exposed to the hydrocarbon feedstock. This is followed by a cool-down period, typically under an inert gas flow. The growth temperature is usually not varied dynamically and the growth is isothermal.