Temperature dependence of kinetic parameters related to oxygen electroreduction in acid solutions on platinum electrodes

Parameter Estimates for a PEMFC Cathode

“…[14][15][16][17][18]20 They are presented in Table I. The remaining five parameters, B , c , i ref , D eff /R a 2 , and eff have to be estimated from the experimental polarization curves.…”

“…After scrutinizing the model equations described in the previous session, we find that B The normal Tafel slope b is a kinetics parameter, which value was measured and reported in the literature. [14][15][16][17][18] This parameter was not included in our estimation. The thicknesses of the GDL and the CAL were measured on a gas diffusion electrode.…”

Size Effects in Electrocatalysis of Fuel Cell Reactions on Supported Metal Nanoparticles

“…The reaction rate is first order with respect to the oxygen partial pressure P O 2 , which implies that the O 2 bond break occurs after or during the ORR rate-determining step (RDS). The reaction order with respect to H þ concentration is equal to 1 1 2 at low and 1 at high current densities [Zinola et al, 1994]. The Tafel slopes for Pt electrodes in acidic solutions have been found to change from about 2120 mV dec 21 in the potential interval below about 0.8 V vs. RHE, where the Pt surface is free from oxide, to about 260 mV dec 21 at higher electrode potentials, where the surface is oxide-covered.…”

Kinetics of Ferric Ion Reduction on Chalcopyrite and its Influence on Leaching up to 150 °C

“…The above-noted unexpected temperature independence for the Tafel slope, as well as the anomalous temperature-dependent transfer coefficient, are not unique to the ferric ion reduction reaction on chalcopyrite and have been observed previously in other systems [76][77][78][79][80][81]. These studies were carried out over a wide range of temperatures.…”