Influence of Heat Treatment on the Microstructure and Functional Characteristics of PtCu/C Catalysts

PtCu/C electrocatalysts with different compositions, obtained by the method of the combined reduction of metal precursors, are heat treated at a temperature of 350°C in an argon atmosphere. The study by X-ray powder diffraction and transmission electron microscopy shows an increase in the average size of nanoparticles after heat treatment, which explains a decrease in the value of the electrochemically active surface area of the catalysts. An increase in the specific activity of the catalysts in the reaction of oxygen electroreduction after heat treatment is shown. The study by stress testing in the potential range of 0.6–1.4 V shows an increase in the stability of the heat-treated catalyst in comparison with the material in the “as prepared” state. A decrease in the amount of dissolved copper from the catalyst nanoparticles after heat treatment during electrochemical activation is shown, which also indicates an increase in catalyst stability.