Carbon-supported PtAu alloy nanoparticle catalysts for enhanced electrocatalytic oxidation of formic acid

• Published in: Journal of power sources 2011-10, Vol.196 (20), p.8323-8330
• Main Authors: Chen, Guoqin, Li, Yunhua, Wang, Dong, Zheng, Li, You, Guirong, Zhong, Chuan-Jian, Yang, Lefu, Cai, Fan, Cai, Junxiu, Chen, Bing H.
• Format: Article
• Language: English
• Subjects: Applied sciences; Bimetallic catalysts; Bimetals; Catalysis; Catalysts; Catalysts: preparations and properties; Chemistry; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrocatalysts; Electrochemical conversion: primary and secondary batteries, fuel cells; Electrochemistry; Electrooxidation of formic acid; Emission analysis; Energy; Energy. Thermal use of fuels; Equipments for energy generation and conversion: thermal, electrical, mechanical energy, etc; Exact sciences and technology; Fuel cells; General and physical chemistry; Inductively coupled plasma; Miscellaneous (electroosmosis, electrophoresis, electrochromism, electrocrystallization, ...); Nanomaterials; Nanostructure; Oxidation; Platinum–gold alloy; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2011.06.048

• Pt100−mAum/C catalysts with controllable bimetallic composition were synthesized. • The correlation for the effect of PtAu bimetallic composition on mass activity was established. • The Pt50Au50/C catalyst exhibits an eight-fold increase of electrocatalytic activity for the oxidation of formic acid in comparison with Pt/C. • The origin of the high activity mainly owes to its high selectivity toward the dehydrogenation of formic acid molecules on the bimetallic alloy surface. The understanding of the electrocatalytic activity of bimetallic nanoparticle catalysts requires the ability to precisely control the composition and phase properties. In this report, we describe a new strategy in the preparation of a series of carbon supported platinum–gold bimetallic nanoparticles with various bimetallic compositions which were loaded onto a carbon black support and subjected subsequently by thermal treatment (Pt100−mAum/C). The Pt100−mAum/C catalysts are characterized by X-ray diffraction (XRD), transmission electron spectroscopy (TEM), and induced coupled plasma-atomic emission spectroscopy (ICP-AES). The XRD pattern for the bimetallic nanoparticles shows single-phase alloy character. This ability enabled us to establish the correlation between the bimetallic composition and the electrocatalytic activity for formic acid (FA) electrooxidation. The electrocatalytic activities of the catalysts toward FA oxidation reaction are shown to strongly depend on the bimetallic PtAu composition. Within a wide range of bimetallic composition, the Pt50Au50/C catalyst shows the highest electrocatalytic activity for the FA oxidation, with a mass activity eight times higher than that of Pt/C. The high performance of the PtAu/C catalyst can be ascribed to the increased selectivity toward the FA dehydrogenation at the decreased availability of adjacent Pt atoms.