Chemical Research in Chinese Universities ›› 2016, Vol. 32 ›› Issue (1): 106-111.doi: 10.1007/s40242-016-5277-5

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Dealloyed Silver Nanoparticles as Efficient Catalyst Towards Oxygen Reduction in Alkaline Solution

CUI Qinghua1,2, ZHANG Yelong1,2, PENG Zhangquan1   

  1. 1. State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China;
    2. University of Chinese Academy of Sciences, Beijing 100049, P. R. China
  • Received:2015-07-17 Revised:2015-08-13 Online:2016-02-01 Published:2015-10-12
  • Contact: PENG Zhangquan E-mail:zqpeng@ciac.ac.cn
  • Supported by:

    Supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA09010401).

Abstract:

Silver nanoparticles(Ag NPs) were prepared by dealloying Mg-Ag alloy precursor. The obtained Ag NPs have an average ligament size of (50±10) nm. Electrocatalytic activity of Ag NPs towards oxygen reduction reaction(ORR) in 0.1 mol/L NaOH solution was assessed via cyclic voltammetry(CV), rotating ring disk elec-trode(RRDE) techniques, and electrochemical impedance spectroscopy(EIS). The electrochemical active area for the ORR was evaluated by means of the charge of the underpotential deposition(UPD) of lead(Pb) on Ag NPs. The CV results indicate that Ag NPs have a higher current density and more positive onset potential than the bulk Ag electrode. RRDE was employed to determine kinetic parameters for O2 reduction. Ag NPs exhibit a higher kinetic current density of 25.84 mA/cm2 and a rate constant of 5.45×10-2 cm/s at -0.35 V vs. Hg/HgO. The number of electrons(n) involved in ORR is close to 4. Further, EIS data show significantly low charge transfer resistances on the Ag NPs electrode. The results indicate that the prepared Ag NPs have a high activity and are promising catalyst for ORR in alkaline solution.

Key words: Silver nanoparticles, Electrochemical activity, Oxygen reduction reaction