Evaluation of the Activity of Metal-Oxides as Anode Catalysts in Direct Methanol Fuel Cell

Abstract

In the present work, pure iridium oxide (IrO2), and ternary catalysts (IrSnSb-Oxides and RuIrTi-Oxides) are investigated to be used as anode electrocatalysts in The Direct Methanol Fuel Cells (DMFC). Investigations of Methanol Oxidation and Hydrogen Evolution over the catalysts are measured in sulphuric acid as a supportive electrolyte using cyclic voltammetry technique at room temperature (25°C). A specific comparison between the electrocatalytic activities of IrSnSb-Oxides and RuIrTi-Oxides systems is conducted. A comprehensive examination of IrSnSb-Oxides and RuIrTi-Oxides catalysts containing different fractions of the alloying elements are performed to study the effect of varying Iridium Ir content (%) in IrSnSb-Oxides and Ruthenium Ru content (%) in RuIrTi-Oxides on the catalytic activity of ternary catalysts and on the performance of DMFC. It is observed that the electrocatalytic performance of ternary oxides catalysts is strongly dependent on the Ir and Ru content. The generated IrO2 and 33.36% Ru – 1%Ir – 65.64%Ti – Oxides catalysts prove high stability for oxidation of methanol and more proficient electrochemical activity as an anodic electrocatalyst in DMFC at 25°C. The electrochemical measurements of the Hydrogen Evolution Reaction (HER) for metal oxides show that 46.65%Ir – 40.78%Sn – 12.57%Sb sample and 18.75%Ru – 9.35%Ir – 71.9%Ti sample are the superior hydrogen evolution catalysts at 25°C.