Formation of carbon supported PtRu alloys: an XRD analysis

• Published in: Journal of alloys and compounds Vol. 315; no. 1; pp. 118 - 122
• Main Authors: Antolini, E., Cardellini, F.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 09.02.2001; Elsevier
• Subjects: Catalysis; Catalysts: preparations and properties; Chemistry; Electrochemistry; Electrode materials; Electrodes: preparations and properties; Exact sciences and technology; General and physical chemistry; Intermetallics; Nanofabrication; Nanostructures; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; X-ray spectroscopy; Intermetallics; Electrode materials; Nanofabrication; Nanostructures; X-ray spectroscopy; Mixed catalyst; Ruthenium; Anode; Intermetallic compound; Transition metal; Nanostructure; Carbon; X ray diffraction; Supported catalyst; Electrodes; Transition metal Alloys; Platinoid Alloys; Ruthenium Alloys; Platinum; Preparation; Platinum Alloys; Platinoid; Fuel cell; Binary alloy
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/S0925-8388(00)01260-3

Carbon supported PtRu alloys were prepared by impregnation of Pt and Ru precursors on a porous carbon support, followed by reduction of the metals with Na 2S 2O 4. After reduction, the samples were thermal treated in argon up to 700°C. The samples were characterized by atomic absorption (AAS) and X-ray diffraction (XRD) measurements. Before thermal treatment only carbon reflexions were visible in XRD pattern. The reflexions of face centered cubic (f.c.c.) PtRu alloy were revealed in XRD pattern starting from thermal treatment at 300°C. No hexagonal close packed (h.c.p.) RuPt reflexions were detected. During thermal treatment, part of Ru reacted with sulphur forming RuS 2. Ru content in the alloy increased with increasing thermal treatment temperature. The results indicated that, first, f.c.c. Pt with few Ru alloyed was formed, then, with increasing thermal treatment temperature, part of Ru atoms present in the sample in an amorphous form entered in the crystal structure of the platinum by a diffusion-controlled mechanism. Also after thermal treatment at high temperatures there was a large part of unalloyed Ru, with only about 49% of the Ru alloyed with the Pt. PtRu particle size was in the range 15–20 nm.