Electrochemical surface area measurements of platinum- and palladium-based nanoparticles

The electrochemical surface area (ECA) calculation was studied using the charges associated with stripping of CO and underpotentially deposited H and Cu on highly dispersed Pt- and Pd-based nanoparticles. The surface areas followed a general trend of H-UPD < CO striping < Cu-UPD. Transition metals in the alloys were found to have a significant effect on the determination of surface area. The surface area could be underestimated by nearly 50% using H-UPD on conventional (non-shape-controlled) PtNi/C. In addition to the effect from Ni, the shape/structure of the nanoparticles also made the calculation more complicated. The surface area could be underestimated by more than two times using H-UPD on octahedral PtNi/C compared to using Cu-UPD. Cu-UPD was demonstrated to be a more accurate method to estimate the electrochemical active areas than H-UPD and CO striping. (c) 2013 Elsevier B.V. All rights reserved.