Highly loaded carbon black supported Pt catalysts for fuel cells

• Published in: Catalysis today 2015-11, Vol.256, p.375-383
• Main Authors: Kaluža, Luděk, Larsen, Mikkel J., Zdražil, Miroslav, Gulková, Daniela, Vít, Zdeněk, Šolcová, Olga, Soukup, Karel, Koštejn, Martin, Bonde, Jacob L., Maixnerová, Lucie, Odgaard, Madeleine
• Format: Article
• Language: English
• Subjects: Carbon black; Electrocatalyst; Fuel cell; Pt deposition; Pt/C
• ISSN: 0920-5861; 1873-4308
• DOI: 10.1016/j.cattod.2015.02.016

•Carbon black supports with surface area 226, 384 and 808m2g−1 compared.•Deposition of PtO2, H2PtCl6, Pt(C5H7O2)2, Pt(NH3)4(NO3)2, and Pt(NH3)2(NO2)2.•H2PtCl6 most suitable by H2 chemisorption and electrochemical RDE analysis.•Dechlorination of the catalysts developed by NaOH and water washing.•Better electrochemical stability of the carbon ExpCB with S(NE)=384m2g−1. A commercial high surface area carbon black (808m2g−1), low surface area carbon black (226m2g−1) and an experimental grade medium surface area carbon black (ExpCB, 384m2g−1) were studied as supports for platinum deposition: (i) from true solutions of H2PtCl6, Pt(C5H7O2)2, Pt(NH3)4(NO3)2, or Pt(NH3)2(NO2)2, and (ii) from fine slurries of Pt(C5H7O2)2 or PtO2 to achieve high Pt loadings of 60wt.%. Temperature programmed reduction (TPR) revealed that PtO2, H2PtCl6, Pt(C5H7O2)2, Pt(NH3)4(NO3)2, and Pt(NH3)2(NO2)2 deposited on carbon blacks were reduced to metallic Pt at 0, 70, 120, 140, 150°C, respectively. Cyclic voltammetry (CV) was carried out on electrodes prepared from selected catalyst materials on a rotating-disc electrode (RDE). The electrochemically active surface area (ESA) of the platinum and electrocatalytic activities towards the oxygen-reduction reaction (ORR) were evaluated from the RDE measurements, in which also the stability towards electrochemical ageing was investigated. These analyses indicated that impregnation by H2PtCl6 is the most suitable of the studied catalyst synthesis methods. Mass-specific ORR activities similar to that of commercial reference catalyst are obtained. Catalysts prepared on carbon ExpCB showed greater stability than those based on 350G. Further increase in stability results from dechlorination of the catalyst.