This work discusses the fabrication and characterization of Pt-Co electrocatalysts for polymer electrolyte membrane fuel cells (PEMFC) and electrocatalysis of the oxygen reduction reaction. Two sets of carbon supported catalysts with Pt:Co in the atomic ratio of 0.25:0.75 and 0.75:0.25 were prepared using a high-energy ball-milling technique. One of the Pt-Co electrocatalysts was subjected to lixiviation to examine the change in surface area. Microstructural characterization of the electrocatalysts was done using scanning electron microscopy, transmission electron microscopy, x-ray diffractometry, and x-ray photoelectron spectroscopy. Electrochemical characterization of the electrocatalysts was done in acidic and alkaline media using cyclic voltammetry and potentiodynamic polarization techniques. These tests were performed at room and higher temperature (50°C). Performances of the electrocatalysts were also compared with the commercial E-TEK Pt:Co alloy electrocatalysts of the compositions 10% Pt-Co alloy (1:1 a/o) and 40% Pt-Co alloy (1:1 a/o) on Vulcan XC-72.

This paper investigates corrosion behavior of Alloy C-22 in hot concentrated brines. The passive film behavior and localized corrosion properties of alloy C-22 as a function of nitrate and sulfate anions in concentrated chloride brines was investigated. Cyclic potentiodynamic polarization tests were used to study the general corrosion behavior of the alloy, Electrochemical Impedance Spectroscopy (EIS) and Mott-Schottky (M-S) were used to examine the electronic properties of the passive films, and constant potential tests were done to study crevice corrosion initiation, propagation and stifling of the alloy. The aim was to investigate the correlation between the electronic properties of the alloy's passive film and the localized corrosion susceptibility of the alloy. The results showed that anions had major impact on the repair-repassivation behavior but did not cause significant effect on the properties of passive film when it was intact.

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