Catalyst geometry dependent single-walled carbon nanotube formation from polyaromatic hydrocarbon molecule: Pt(111) surface versus Pt nanoparticle

Abstract

The chirality controllable synthesis of single-walled carbon nanotubes (SWCNTs) by the catalytic transformation of designed large polyaromatic hydrocarbon molecules has made significant progress in recent years, but the underlying mechanism, such as the role of the catalyst, has never been revealed at the atomic level. In this study, the energy profiles of the dehydrogenation processes from the C60H30 molecule to a (6,6) SWCNT seed on a Pt (111) surface and a Pt55 particle are calculated using first-principles calculations. Our calculations clearly demonstrate that the SWCNT formation process is catalyst geometry dependent, and that it is substantially easier on a curved catalyst surface, i.e., the Pt55 particle, than on a flat Pt(111) surface. Furthermore, catalytic reactions involving Pt adatom on the catalyst surface can considerably reduce the dehydrogenation barriers. This study reveals that employing catalyst particles to synthesize SWCNT from polyaromatic hydrocarbon molecule is a better approach for chirality-controlled SWCNT development.