Evaluation of colloidal Os and Os-Alloys (Os–Sn, Os–Mo and Os–V) for electrocatalysis of methanol and borohydride oxidation

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• 作者：Mohammed H. Atwan ; Derek O. Northwood and Elod L. Gyenge
• 关键词：Electrocatalysis ; Methanol oxidation ; Borohydride oxidation ; Voltammetry
• 刊名：International Journal of Hydrogen Energy
• 出版年：2005
• 出版时间：2005
• 年：2005
• 卷：30
• 期：12
• 页码：1323-1331
• 全文大小：310 K

文摘

The oxidation of methanol and sodium borohydride (NaBH₄) on supported colloidal Os and Os-alloys (i.e. Os–Sn, Os–Mo and Os–V) have been studied by voltammetry and chrono-techniques (i.e., potentiometry, amperometry). The electrolytes were: 0.5 M H₂SO₄ for methanol oxidation and 2 M NaOH (without and with thiourea (TU)) for borohydride oxidation, respectively. Voltammetry results showed that the investigated Os-based materials were catalytically inactive with respect to methanol oxidation, contradicting therefore, the theoretical suggestion by Kua and Goddard [J Am Chem Soc 1999; 121:10928–41] indicating electrocatalytic activity for Os toward methanol oxidation. Regarding the oxidation of borohydride, for direct borohydride fuel cells, preliminary results showed a voltammetric wave, with oxidation potentials between 0.1 and 0.3 V vs. Ag/AgCl, KCl_std, which were attributed to borohydride and TU oxidation. Chronopotentiometry results of Os-alloys showed a more positive operating potentials compare to colloidal Os catalysts.