Oxide-supported PtCo alloy catalyst for intermediate temperature polymer electrolyte fuel cells

• Published in: Applied catalysis. B, Environmental Environmental, 2013-10, Vol.142-143, p.15-24
• Main Authors: Stassi, Alessandro, Gatto, Irene, Baglio, Vincenzo, Passalacqua, Enza, Aricò, Antonino S.
• Format: Article
• Language: English
• Subjects: Applied sciences; Catalysis; Catalysts; Chemical Sciences; Chemistry; Crystallites; Direct energy conversion and energy accumulation; Doped Ti-oxide support; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Electrolytes; 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; Intermediate temperature; Material chemistry; Oxides; Oxygen reduction reaction; Pt catalysts; Relative humidity; Tantalum; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Titanium
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2013.05.008

•Good performance is obtained for PtCo alloy/Ta-doped Ti-oxide for ORR in PEMFCs.•High electrochemical stability is shown by PtCo/Ta-doped Ti-oxide at 1.4V RHE.•Oxide support shows promoting effect for ORR at intermediate temperatures (110°C).•Higher performance is achieved with Pt–Co/oxide vs. Pt/oxide in PEMFCs. A Pt–Co alloy catalyst supported on a Ta-doped Ti-oxide was investigated for the oxygen reduction reaction in a polymer electrolyte fuel cell (PEMFC) operating between 80 and 110°C at different relative humidity (100% and 33% R.H.). A crystalline anatase phase was obtained for the Ta-doped Ti-oxide support with BET surface area of about 150m2/g. Pt and Pt3Co1 nanoparticles dispersed on the Ta-doped Ti-oxide showed a crystallite size of 3.9 and 2.9nm, respectively. These catalysts were investigated in PEMFC and benchmarked against a carbon supported Pt3Co1 of similar crystallite size (Pt3Co1/C). Under automotive relevant operating conditions, i.e. at intermediate temperatures (110°C), and in the presence of low relative humidity (33% R.H.), the oxide-supported PtCo was approaching in performance the Pt3Co1/C catalyst. The performance of PtCo/oxide was better than that of Pt/oxide under all operating conditions. The oxide supported PtCo catalyst showed a lower electrochemically active surface area (ECSA) and larger ohmic resistance with respect to the Pt3Co1/C. On the other hand, the oxide-supported catalysts appeared stable during an accelerated corrosion test at 1.4V RHE while a dramatic decrease of the ECSA was observed for the Pt3Co1/C under the same condition. Thus, the oxide supported PtCo alloy catalyst appears promising in terms of electrochemical stability and for automotive applications.