Multi-walled carbon nanotube (MWCNT)-supported silver nanocatalyst Ag/MWCNT and binary silver-based nanocatalysts Ag-x-Me-y/MWCNT (molar ratio x:y = 9:1,8:2, 7:3; Me = Co, Cu, Ni, Sn) have been synthesized by using the NaBH4 reduction method. All catalysts have been studied in terms of structure and morphology by using X-ray diffraction (XRD) and transmission electron microscopy (TEM) analyses. Their electrocatalytic activity for oxygen reduction reaction (ORR) in 1 mol L-1 NaOH solution has been investigated with the linear scanning voltammetry on a rotating disk electrode. Results show that in terms of the ORR current density, Ag8Co2/MWCNT is the best among the three binary Ag-Co/MWCNT catalysts, Ag9Cu1/MWCNT is the best among the three binary Ag-Cu/MWCNT catalysts, Ag9Ni1/MWCNT is the best among the three binary Ag-Ni/MWCNT catalysts, and Ag9Sn1/MWCNT is the best among the three Ag-Sn/ MWCNT catalysts. Their ORR current density follows the order: Ag8CO2/MWCNT > Ag9Ni1/MWCNT > Ag9Cu1/MWCNT > Ag9Sn1/MWCNT > Ag/MWCNT. The onset potential of ORR on the Ag8Co2/MWCNT is 0.005 V, which is slightly higher than that on the Ag/MWCNT. However, the Ag8CO2/MWCNT exhibits a much higher ORR diffusion current density of 3.16 mA cm(-2)@-0.3 Vat 1600 rpm than the Ag/MWCNT. A four-electron reaction of ORR on the as-synthesized binary Ag-based catalysts is more dominant than a two-electron reaction. In addition, these catalysts are electrochemically inactive to methanol oxidation, showing high alcohol-tolerance. (C) 2014 Elsevier B.V. All rights reserved.