Abstract. Nanostructures often have unusual properties that are linked to their small size. We report here on extraordinary chemical properties associated with the edges of two-dimensional MoS₂ nanoclusters, which we show to be able to hydrogenate and break up thiophene (C₄H₄S) molecules. By combining atomically resolved scanning tunnelling microscopy images of single-layer MoS₂ nanoclusters and density functional theory calculations of the reaction energetics, we show that the chemistry of the MoS₂ nanoclusters can be associated with one-dimensional metallic states located at the perimeter of the otherwise insulating nanoclusters. The new chemistry identified in this work has significant implications for an important catalytic reaction, since MoS₂ nanoclusters constitute the basis of hydrotreating catalysts used to clean up sulfur-containing molecules from oil products in the hydrodesulfurization process.

Print publication: Issue 3 (March 2003)
Received 23 January 2003
Published 5 February 2003