In situ electrochemical AFM monitoring of the potential-dependent deterioration of platinum catalyst during potentiodynamic cycling

Abstract

A platinum catalyst undergoes complex deterioration process during its operation as a cathode in a proton exchange membrane fuel cell. By using in situ electrochemical atomic force microscopy (EC-AFM) with super-sharp probes, we quantitatively describe the roughening of platinum thin films during electrochemical cycling to different upper potentials, which simulate critical operation regimes of the proton exchange membrane fuel cell. The comprehensive quantitative analysis of morphology changes obtained using common roughness descriptors such as the root mean square roughness, the correlation length and the roughness exponent is correlated with cyclic voltammetry performed simultaneously.

Keywords: Correlation length; Cyclic voltammetry; Electrochemical AFM; Height–height correlation function; Platinum; RMS roughness.