Interaction of Hydrogen with Au Modified by Pd and Rh in View of Electrochemical Applications

FERNANDA JUAREZ; HAZAR GUESMI; GERMAN SOLDANO; FREDERIK TIELENS; ELIZABETH SANTOS; TZONKA MINEVA

Information and Computation

ACADEMIC PRESS INC ELSEVIER SCIENCE

Año: 2016 vol. 4

0890-5401

Hydrogen interaction with bimetallic Au(Pd) and Au(Rh) systems are studied with thedensity functional theory (DFT)-based periodic approach. Several bimetallic configurations withvarying concentrations of Pd and Rh atoms in the under layer of a gold surface(111) were considered.The reactivity of the doped Au(111) toward hydrogen adsorption and absorption was related to theproperty modifications induced by the presence of metal dopants. DFT-computed quantities, suchas the energy stability, the inter-atomic and inter-slab binding energies between gold and dopants,and the charge density were used to infer the similarities and differences between both Pd andRh dopants in these model alloys. The hydrogen penetration into the surface is favored in thebimetallic slab configurations. The underlayer dopants affect the reactivity of the surface gold towardhydrogen adsorption in the systems with a dopant underlayer, covered by absorbed hydrogen up toa monolayer. This indicates a possibility to tune the gold surface properties of bimetallic electrodesby modulating the degree of hydrogen coverage of the inner dopant layer(s).