Electrooxidation of methanol and ethanol in acidic medium using a platinum electrode modified with lanthanum-doped tantalum oxide film

In this work, lanthanum-doped tantalum oxide (La-Ta2O5) particles were synthesized for the methanol and ethanol oxidation. X-ray diffractometry (XRD) revealed that the Ta2O5 cells swelled after lanthanum doping. X-ray photoelectron spectroscopy (XPS) indicated that the state of lanthanum on Ta2O5 surface is trivalent. The electronic structure of La-Ta2O5 was calculated using density functional theory (DFT) and this indicated that the band gap of Ta2O5 is narrow when it is doped with lanthanum, which explains the improvement in the conductivity and electrocatalytic activity of the Ta2O5. The electrocatalytic activity of a Pt electrode modified with La-Ta2O5 film (La-Ta2O5/Pt electrode) was investigated in a solution of 0.5 mol dm−3 H2SO4 and 1 mol dm−3 methanol (ethanol) using cyclic voltammetry (CV). The CV results indicated that the La-Ta2O5/Pt electrode has high electrocatalytic activity toward the methanol and ethanol oxidation.