Hydrogen adsorption and fractional conductance of electrochemical nanowires

E. SANTOS, G. SOLDANO, P. QUAINO AND W. SCHMICKLER

ELECTROCHEMISTRY COMMUNICATIONS

Elsevier

Año: 2009 vol. 11 p. 1764 - 1774

1388-2481

A theory for electrocatalysis devised in the authors’ group is combined with density functional theory to investigate the electro- chemical reactivity of monoatomic nanowires towards hydrogen. On Cu and Au wires, hydrogen atoms are much more strongly adsorbed than on planar surfaces of the bulk metal, while on Ag adsorption is weak. These results explain recent observations of fractional conductances on electrochemical Cu and Au nanowires in the hydrogen evolution region. Free energy surfaces for the ad- sorption and discharge of the proton show low activation barriers of the order of 0.1 eV for Au and 0.5 eV for Cu. Thus, both Au and, most surprisingly, Cu wires promise to be good catalysts for hydrogen evolution.