Activated carbon and poly-o-anisidine(POA) synergistic supported Pt nanoparticles as a highly efficient catalyst for electrocatalytic oxidation of formaldehyde

Abstract

In this work, different mass percentage of activated carbon (YBC) doped carbon paste electrodes (YBCPE) were firstly prepared, then electrodeposition of Pt nanoparticles was performed at a constant potential -0.1 V vs. Ag|AgCl|KCl (3 M) to prepare working electrodes Pt/YBCPE. It was shown that Pt/YBCPE(16%) exhibits the highest mass activity for formaldehyde oxidation compared to platinum deposited on pure carbon paste electrode (CPE) and other YBCPE(X%) electrodes. Afterwards, poly-o-anisidine (POA) film was prepared by electro-polymerization onto the CPE and YBCPE(16%) in o-anisidine monomer solution at 0.7 V and then Pt nanoparticles were electro-deposited at the POA film surface for fabrication of the Pt/POA/CPE and Pt/POA/YBCPE composite electrodes. The morphology of the composite electrodes was characterized by SEM, TEM, XRD and XPS which revealed that the presence of YBC and POA in the composite electrodes significantly improves the dispersion of Pt nanoparticles on the electrodes. Electrochemical impedance spectroscopy (EIS), chronoamperometry and cyclic voltammetry were used to verify the conductivity and durability of the composite electrode and its electro-catalytic activity. The obtained results indicated that the Pt/POA(16mC)/YBCPE(16%) exhibits excellent electro-catalytic activity towards the formaldehyde oxidation owing to the synergistic effect of the support-catalyst. Some comparisons for the electrooxidation of formaldehyde and the electrooxidation of methanol and formic acid on the composite electrodes also were conducted.