AbstractThe electrical resistance (R) of nanoporous platinum prepared by dealloying reversibly changes by 4% upon electrochemical surface charging in a regime where oxygen adsorption/desorption and surface oxidation/reduction occur. The variation of R with charging shows a sign inversion. Besides the usual behavior of increasing R with positive charging, a decrease of R occurs at higher potentials. Following recent studies of the sign inversion of the surface stress-charge response of porous nanophase Pt, the sign-inversion of the resistance with charging may be related to the electronic structure of the surface oxide. In addition, a charge-induced variation of the charge-carrier scattering rate at the metal–electrolyte interface is taken into account.