One-Pot Synthesis of Pt–Fe for EOR: Effect of pH

Abstract

The development of efficient electrocatalysts for the ethanol oxidation reaction (EOR) remains a major challenge for direct ethanol fuel cells (DEFCs) due to slow kinetics and catalyst poisoning by reaction intermediates. Herein, Pt/C and Pt–Fe/C catalysts were prepared via a one-pot polyol synthesis, and the effect of pH on Fe incorporation and catalytic performance was investigated. X-ray diffraction showed lattice contraction in Pt–Fe catalysts, confirming Fe incorporation, which was more pronounced under alkaline conditions. Electrochemical measurements demonstrated a strong dependence on both Fe addition and pH. Pt–Fe/C at pH 11.4 achieved a mass activity density of 850 A/gPt, outperforming not only Pt–Fe/C neutral and Pt/C but also the commercial Pt/C catalyst at 20 mV/s. Moreover, a lower onset potential (0.479 V) and a higher If/Ib ratio (1.9) indicate faster reaction kinetics and qualitatively suggest tolerance to adsorbed intermediates. The enhanced performance is attributed to the synergistic effect of Fe incorporation through electronic and bifunctional mechanisms.