Preparation of Pt–Ru Alloyed Thin Films Using a Single‐Source CVD Precursor

Treatment of (dimethylaminomethyl)ruthenocene with cis‐Pt(DMSO)2Cl2 led to the formation of a ruthenocenyl platinum complex [CpRu(η5‐C5H3CH2NMe2)Pt(DMSO)Cl] (1); subsequent treatment of 1 with [Na(hfac)] afforded an air‐stable Pt–Ru complex [CpRu(η5‐C5H3CH2NMe2)Pt(hfac)] (2). Its volatility and other physical data relevant to CVD experiments were assessed by thermogravimetric analysis (TGA). The Pt–Ru thin films were then deposited at two deposition temperatures, 300 °C and 400 °C, using O2 as the reactive carrier gas. The as‐deposited thin films were characterized using energy dispersive X‐ray (EDX), scanning electron microscopy (SEM), X‐ray photoelectron spectroscopy (XPS), and X‐ray diffraction (XRD). Results indicated the formation of a homogeneous Pt–Ru solid solution at the lower deposition temperature. However, upon raising the temperature to 400 °C, phase separation between Pt and Ru occurred, which then induced the growth of RuO2 grains at the substrate surface and caused depletion of the alloy in ruthenium. The electrocatalytic activities of the films, in respect of methanol oxidation, were investigated, in half‐cell experiments, by cyclic voltammetry.