Electrocatalytic Oxidation of Methanol Over Silver-Based Ag-M/C (M = Cu, Zn, Fe, Cr, Mn) Electrocatalysts Synthesized by Solution Combustion Technique

Abstract

Herein, we report the electrocatalytic properties of Ag-M/C (M = Cu, Zn, Fe, Cr, Mn) catalysts synthesized using solution combustion synthesis (SCS) method for methanol oxidation reaction (MOR). The morphological properties of the synthesized catalysts were studied using SEM, EDX, TEM, XRD and XPS techniques. The results indicated AgCu/C to be the most porous catalyst with small and well distributed nanoparticles making it a suitable choice for electrocatalytic applications. The XPS results showed a shift in peak in the AgCu/C sample due to the charge transfer between Ag and Cu indicating a strong interaction in the compound. The electrochemical measurements in 1 M methanol with 1 M KOH electrolyte by cyclic voltammetry (CV) and linear sweep voltammetry (LSV) revealed that AgCu/C showed high electrocatalytic activity for MOR. Further studies on AgCu/C for methanol concentrations of 0.5 M, 1 M, 1.5 M, 2.5 M to evaluate the rate dependency of the catalyst indicated a power-law dependency with an order of 0.55 on methanol concentration. According to chronoamperometry analysis, the catalyst was stable for at least 20 h.