Catalytic properties of graphite-supported nanowires – a DFT study

GERMAN SOLDANO; PAOLA QUAINO; ELISABETH SANTOS; WOLFGANG SCHMICKLER

Nice

Congreso; The 61st Annual Meeting of the International Society of Electrochemistry. Electrochemistry from Biology to Physics; 2010

International Society of Electrochemistry - ISE

The stability of coinage and noble metal nanowires supported on graphite steps isexamined by density functional theory. In particular, we study the stability of supportedAu, Ni, Pt and Pd wires and compare their chemical properties with those of surfacesand bare wires. Two configurations for the step edge are considered: zigzag andarmchair. The wire-graphite interaction is describe in detailthrough density of states (DOS) and charge density difference analysis.A substantially stronger bond with graphite was found for the Ni group wires due tounfilled antibonding states, which are occupied in the case of Au. This difference hasdirect consequences for the adsorption of hydrogen. The reaction can occur either onthe wire or directly on graphite steps. In the case of Au, the reaction is favoured onsteps, while on Pt wires, it has no thermodynamical preferences. Our results suggestthat, in early stages of wire formation, hydrogen could desorb Au from graphite, butnot Pt.