Electrochemical promotion and metal-support interaction (MSI) have long been viewed as two separate phenomena; however, more recently it has been shown that, functionally, for ionic and mixed ionic-electronic conducting materials, both are linked by the transfer of ionic species at the interfaces. The purpose of this study was to exhibit a relationship between these two concepts through the use of an electrochemical technique to evaluate CeO2-supported Pt- and Ru-based nanoparticles. The presence of ceria was found to increase the reaction rate when compared to free-standing Pt and Ru nanoparticles with the metal-support interaction rate enhancement ratios, ρMSI, up to 14. Polarization measurements established that higher exchange current density, i0, values correspond to lower open circuit catalytic rates. An apparent self-induced Faradaic efficiency was proposed and determined for each catalyst; lowest value (|ΛMSI| =1053) corresponded to 1 wt% Pt-1/CeO2.
Journal of Catalysis333 (18 November 2015): 40–50.