Electrooxidation of Methanol on Pt, Ru, and Metal Oxides Nanoparticles Modified with Polyaniline-Carbon Nanotube Hybrid Electrodes

Abstract: Direct methanol fuel cells (DMFCs), as an important alternative energy source for portable devices, have attracted considerable interest because of the high energy density of methanol, the simplicity of processing it as a fuel, and the suitability of storage as a liquid fuel. Nevertheless, fuel cell catalysts suffer from strong adsorption of CO on platinum, which leads to poison on the catalyst’s surface and the prevention of further oxidation of methanol. Improvements are needed in terms of lowering the number of precious metals required for large-scale applications. Carbon powder, carbon nanotubes, and conducting polymer matrix are shown to have high electrocatalytic performance. Consequently, platinum loading has been diminished pointedly with improved Pt utilization. In this sense, particularly in the current study, the electrooxidation of methanol was investigated on Pt, Ru, and metal oxide nanoparticles such as V₂O₅ and WO₃, modified by polyaniline (PANI)-functionalized multi-wall carbon nanotubes (fCNTs) composite electrodes in terms of DMFCs and related applications. Only electrochemical techniques were utilized throughout the synthesis of electrodes. The citrate method was utilized for preparing all of the metal and metal oxide nanoparticles. A comparative study was realized in each step of the experimental study. It was seen that ternary alloy nanosized electrodes showed much more activity than those of mono or bimetallic systems. The prepared electrodes were viewed and analyzed by SEM, EDX, Raman, and TEM techniques. Moreover, kinetic studies were carried out to determine important parameters. As a concluding remark, the current research presents a highly feasible procedure to produce PANI–fCNTs/Pt–Ru–metal oxide nanoparticle composite materials.