Carbon nanotubes-supported colloidal Ag-Pd nanoparticlesas electrocatalysts toward oxygen reduction reaction inalkaline electrolyte

摘要

Ag-Pd nanoparticles with compositional ratios of 1:1 (Ag_1Pd_1), 2:1 (Ag_2Pd_1), and 4:1 (Ag_4Pd_1) and supported on multiwall carbon nanotubes (CNTs) were prepared by the self-regulated reduction of sodium dodecyl sulfate, and then, they were used as catalysts for oxygen reduction reactions (ORRs) in 1 M NaOH solution. Polarization curves showed that, among the prepared nanocatalysts, Ag_4Pd_1/CNT nanocatalysts showed higher activity. During the ORRs, two types of oxygen coverages given by the Temkin isotherm and Langmuir isotherm were observed for low and high overpotentials, respectively. Koutecky-Levich plots showed that the number of electrons involved in the ORRs catalyzed by AgiPdj/CNT, Ag_2Pd_1/CNT, and Ag_4Pd_1/CNT were 2.11,1.88, and 2.25, respectively. These ORRs proceeded through a two-electron pathway. Polarization curve in the electrolyte with methanol revealed that Ag_4Pd_1/CNT has high methanol tolerance during ORRs.