Magic Graphene Clusters Formation in the graphene CVD growth process on Ru and Rh

TL;DR

This study uses ab initio calculations and kinetic analyses to identify ultra-stable graphene-related carbon clusters on Ru and Rh surfaces, revealing their structures and formation mechanisms crucial for controlled CVD graphene growth.

Contribution

It uncovers specific stable carbon cluster structures, especially C21-3C, and explains their stability and formation process on catalyst surfaces, advancing understanding of graphene nucleation.

Findings

Identified ultra-stable C21-3C cluster as a key graphene nucleus candidate

Explained stability due to core structure and surface passivation

Provided insights into cluster formation on Ru and Rh surfaces

Abstract

To improve atomically controlled chemical vapor deposition (CVD) growth of graphene, understanding the evolution from various carbon species to a graphene nuclei on various catalyst surfaces is essential. Experimentally, an ultra-stable carbon cluster on Ru(0001), Rh(111) surfaces was observed, while its structure and formation process were still under highly debate. Using ab initio calculations and kinetic analyses, we disclosed a specific type of carbon clusters, composed of a C21 core and a few dangling C atoms around, were exceptional stable in the size range from 21 to 27. The most stable one of them, an isomer of C24 characterized as three dangling C atoms attached to the C21 (denoted as C21-3C), is the most promising candidate for the experimental observation. The ultra-stability of C21-3C originates from both the stable core and the appropriate passivation of dangling carbon atoms by the catalyst surface.