Electrochemical area of graphene-supported metal nanoparticles from an atomistic approach

JIMÉNEZ-GARCÍA, JUAN C.; OLMOS-ASAR, JIMENA A.; FRANCESCHINI, ESTEBAN E.; MARISCAL, MARCELO M.

JOURNAL OF APPLIED ELECTROCHEMISTRY

SPRINGER

Año: 2020 vol. 50 p. 421 - 429

0021-891X

In electrochemical catalysis, parameters such as current, resistance, or capacitance must be referred to the electrochemicallyexposed area, otherwise they lack physical sense. For this reason it is necessary to know this exposed area as accurately aspossible. Although there are several experimental methods to estimate the electrochemically exposed area, these are usuallynot suitable for diferent metals and present large errors in measurements, for example when two or more metals aremixed. Moreover, the technical diiculties of carrying out this type of measure means that it is often necessary to resort toapproximations with great error, such as the spherical approach, with the aim of having an approximate value of the area.In this work, molecular dynamic simulations were performed to study the morphology of graphene-supported nanoparticles.A method for the calculation of the electrochemically active surface area is proposed and tested for Pt, Au, and Pt/Aunanoalloys. These results are compared with existent experimental data and a model is proposed for the calculation of theelectrochemically active area for supported nanoparticles of diferent sizes.