Electrochemical degradation of electrodeposited Pt particles on mask scratched substrate using a landmark for ex situ scanning electron microscopy

► A mask scratched substrate with a landmark allows an ex situ SEM at the same point. ► The Pt particles are degraded by potential cycling at 100 mmol dm−3 H2O2. ► The Pt particle degradations depend on the potential cycling range. ► The dissolved Pt is re-deposited during the potential cycling in 0.01-0.4 V vs. RHE. ► The deposition of the dissolved Pt affects the change in the Pt particle degradations.