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Carbon-supported PtM nanostructured materials (M = Cr, Co, Ni, Cu, Mo, Y, Sm, Gd) were investigated for the hydrogen evolution/oxidation reactions (HER/HOR) in alkaline medium. All catalysts were synthesized by the carbonyl complex chemical route. Among PtM, Cr, Co, Ni, and Cu formed nanoalloys. M2O3 was generated with Y, Sm, and Gd, and Mo was found at a dopant concentration of Pt. The electrochemical results showed that the HER/HOR activities on PtNi/C and PtCo/C outperformed that of the Pt/C benchmark. The presence of OHads species, acting as a bifunctional mechanism, favored the HER/HOR activity on PtNi/C and PtCo/C. This process is concomitant with early DFT studies that concluded that the presence of OHads weakens the Hads and H2Oads energetics.

Conducting polypyrrole (PPy)/C (Vulcan XC-72) composite materials were synthesized by chemical polymerization method. These materials were used as matrix to support platinum nanoparticles, which were produced by the carbonyl chemical route. For the same catalyst loading (50 μg cm−2), it was observed that the nature of the composite strongly influences the electrochemical activity of nanoparticulated platinum toward the oxygen reduction reaction in acid medium. The variation of the PPy/C ratio determines the so-called substrate effect for electrocatalysis.