Water dimer diffusion on Pd[111] assisted by an H-bond donor-acceptor tunneling exchange.
Based on the results of density functional theory calculations, a novel mechanism for the diffusion of water dimers on metal surfaces is proposed, which relies on the ability of H bonds to rearrange through quantum tunneling. The mechanism involves quasifree rotation of the dimer and exchange of H-bond donor and acceptor molecules. At appropriate temperatures, water dimers diffuse more rapidly than water monomers, thus providing a physical explanation for the experimentally measured high diffusivity of water dimers on Pd[111] [Science 297, 1850 (2002)]].
Ranea
V A
VA
Instituto de Ciencia de Materiales, Consejo Superior de Investigaciones Cientificas, Cantoblanco, E-28049 Madrid, Spain.
Michaelides
A
A
Ramírez
R
R
de Andres
P L
PL
Vergés
J A
JA
King
D A
DA