Effect of borohydride as reducing agent on the structures and electrochemical properties of Pt/C catalyst

doi:10.1016/j.apsusc.2005.11.089

Applied Surface Science

Volume 252, Issue 24, 15 October 2006, Pages 8593-8597

https://doi.org/10.1016/j.apsusc.2005.11.089 Get rights and content

Abstract

In this paper, we found that boron deposited on the surface of support when sodium borohydride used as reducing agent during the preparation of Pt/C catalyst. The deposition of boron markedly reduces particle size of Pt, raises electrochemical active surface (EAS) area of catalyst and electrochemical activity for hydrogen evolution or oxygen reduction reaction (ORR) compared with which prepared using other reducing agents (hydrogen and formaldehyde).

Section snippets

Experimental

The 20 wt.% Pt/C catalyst was synthesized by following process: appropriate amount of precursor H₂PtCl₆ and Vulcan XC-72 carbon were mixed. The mixture was ultrasonicated for 30 min and was reduced by adding 0.05 mol/L NaBH₄ aqueous solution dropwise (Pt/B molar ratio is 1:20) at 60 °C. Subsequently, the formed Pt/C catalyst was filtered, washed with excess de-ionized water and dried in a vacuum oven at 80 °C for 2 h. Henceforth, this catalyst will be named as B-Pt.

The 20 wt.% Pt/C catalyst was also

Results and discussion

X-ray diffraction patterns of Pt/C catalysts which synthesized using various reducing agents are shown in Fig. 1. The samples B-Pt and H₂-B-Pt show broader reflections compared with samples HCHO-Pt and H₂-Pt, indicating a smaller particle size for the formers (see Table 1). On the other hand, when sodium borohydride was employed during preparation of Pt/C catalyst, the characteristic diffraction peaks of Pt(2 2 0), Pt(3 1 1) and Pt(2 2 2) mostly cannot be observed (see Fig. 1). Even these

Acknowledgements

This work was supported by 973 Program (G2000026408), 863 Program (2001AA323060, 2003AA517060) of Science and Technology Ministry of China, The National Natural Science Foundation of China (General Program 20373068, Key Program 20433060) and Natural Science Foundation of Jilin Province (20000510).

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Effect of borohydride as reducing agent on the structures and electrochemical properties of Pt/C catalyst

Abstract

Section snippets

Experimental

Results and discussion

Acknowledgements

J. Power Sources

J. Power Sources

Mater. Chem. Phys.

J. Electroanal. Chem.

J. Power Sources

Electrochem. Commun.

Electrochim. Acta

Catal. Today