Effect of pretreatment atmosphere on the particle size and oxygen reduction activity of low-loading platinum impregnated titanium carbide powder electrocatalysts

JOURNAL OF POWER SOURCES

卷:287

Article

Yang, Leerang¹  Kimmel, Yannick C.²  Lu, Qi^1,2  Chen, Jingguang G.¹ 

[1] Columbia Univ, Dept Chem Engn, New York, NY 10027 USA

[2] Univ Delaware, Dept Chem & Biomol Engn, Newark, DE 19716 USA

关键词: Oxygen reduction reaction;    Titanium carbide;    Impregnation synthesis;    Platinum;   

DOI  :  10.1016/j.jpowsour.2015.03.146

来源: Elsevier

【 摘 要 】

Low-loading Pt supported on TiC powder catalysts were synthesized by an impregnation method. After the Pt(NH3)(4)(NO3)(2) precursor was impregnated onto the TiC support different pretreatment atmospheres were used to study the influence on Pt dispersion, surface composition, and catalytic activity towards oxygen reduction reaction (ORR). Direct reduction of the Pt precursor in hydrogen led to small Pt particles with an average size of similar to 2.2 nm and superior ORR activity at low overpotential compared to commercial Pt/C. However, calcination of the Pt precursor in air resulted in larger Pt particles with an average size of similar to 6.7 nm and lower ORR specific activity. The decrease in ORR activity was primarily attributed to the surface oxidation of the TiC support during calcination. X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) confirmed that the TiC powder was oxidized when the catalyst was calcined in air. The finding reported here demonstrates the importance of pretreatment atmosphere for synthesizing Pt-modified transition metal carbides as highly active electrocatalysts. (C) 2015 Elsevier B.V. All rights reserved.

【 授权许可】

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