Dioxygen reduction by nitrogen-rich mesoporous carbon bearing electrodeposited silver particles

Abstract

The electrocatalytic activity of silver particles supported on nitrogen-containing mesoporous carbon materials (NMC) was studied with a view to dioxygen reduction. Silver particles with controlled size and shape on the NMC were synthesized by a double-pulse electrodeposition technique. Changing the nucleation and growth potential as well as their growth times resulted in varied morphologies of the electrodeposited silver. The effect of the supporting material itself on the activity was assessed by employing variably pyrolyzed NMC supports. The associated kinetic parameters were evaluated by hydrodynamic measurements in alkaline medium. The dioxygen reduction activity was associated with the available surface area, which was determined by double-layer capacitance measurements. The stability of the catalyst was tested by chronoamperometric measurements both in the presence and absence of methanol. Elemental components were identified by X-ray diffraction and X-ray photoelectron spectroscopy techniques. An active and non-platinum electrocatalyst: Silver nanoparticles electrodeposited on a nitrogen-rich mesoporous carbon support exhibited enhanced current density and low overpotential for the oxygen reduction reaction.