Investigation of electrocatalytic activity and stability of Pt anode catalyst on the electrooxidation of 1,2-propanediol, 2-propanol and methanol in alkaline media

Abstract

Carbon-supported platinum nanoparticles are successfully synthesized and characterized by scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDX). Electrocatalytic activity and stability of the Pt/C catalyst for 1,2-propanediol, 2-propanol and methanol electrooxidation was investigated using cyclic voltammetry (CV), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS). According to the obtained results, the activity of the Pt/C catalyst for 1,2-propanediol oxidation reaction was higher than that of the other alcohols. Multi-scan cyclic voltammetry after 100 CV cycles revealed that the Pt/C catalyst has great catalytic activity, high poison-tolerance ability and improved electrochemical stability for 1,2-propanediol oxidation compared with methanol and 2-propanol. This indicates a lower poisoning effect of the adsorbed intermediates on the Pt/C performance in 1,2-propanediol oxidation. Infrared spectroscopy measurements after 100 CV cycles in methanol oxidation indicated that adsorbed CO specie is detected on the surface of Pt/C catalyst, but not in 1,2-propanediol oxidation. Comparison of the corresponding EIS measurements after 1st and 100th cycles showed that 1,2-propanediol has the best performance in terms of charge transfer resistance and specific capacitance.