Abstract

When a cool N₂-CO₂ co-gas stream flows over superheated activated carbon (AC) flakes, a vortex field near the interface is induced as a consequence of the confrontation of the cool co-gas stream and the hot vaporized carbon stream, where the pre-deposited Pt atom clusters on AC catalyze gasification of AC by CO₂ to produce CO, and the CO undergoes immediate disproportionation to release carbon atoms in vapor form. The vortex field functions as a dynamic template for deposition of carbon vapor, leading to the proliferation of nano-sized carbon needles with characteristic spikes (ca. 1µm) and short in length through an anisotropic assembling of carbon atoms. A trace amount of Pt pre-coated on the AC flakes is sufficient to catalyze gasifying AC by CO₂. This phenomenon is the first observation over the surface of amorphous carbon via catalytic pyrolysis without electric potential assistance.