High performance Pt nanoparticles prepared by new surfactants for C₁ to C₃ alcohol oxidation reactions

In this study, platinum nanoparticles have been prepared using PtCl₄ as a starting material and 1-hexylamine, N-methylhexylamine, N,N-dimethylhexylamine, 1-heptylamine, N-methylheptylamine, and N,N-dimethylheptylamine as surfactants. All these surfactants were used in this synthesis, for the first time, to explore the effect of primary, secondary, and tertiary amine and chain length on the size and catalytic activity toward C1–C3 alcohol electro-oxidation. The electrochemical performance of all catalysts was determined using cyclic voltammetry and chronoamperometry. These techniques indicate that the highest electrocatalytic performance was generally observed when electrochemical surface area (ECSA), percent platinum utility, roughness factor, and the number of CH₃ groups attached to the nitrogen atom is higher and the chain length shorter (C₆H₁₃). In addition, other important properties such as the crystal structure of platinum, size, and distribution of the platinum nanoparticles on the carbon support, and Pt(0) to Pt(IV) ratio, were determined using X-ray photoelectron spectroscopy, X-ray diffraction, atomic force microscopy, and transmission electron microscopy. It was found that increasing ECSA, Pt(0)/Pt(IV) ratio, % Pt utility, and roughness factor improves the C1–C3 alcohol oxidation catalytic performance.