Nanosized Composite Electrodes Based on Polyaniline/Carbon Nanotubes Towards Methanol Oxidation

Abstract

Background: Direct methanol fuel cells as a clean and efficient energy conversion method for portable electronic devices and electric vehicles are a very popular subject in science and engineering. Up to now, the most effective anode electrode materials for direct methanol fuel cells are Pt- Ru, used mainly as bimetallic catalysts dispersed on a highly active conductive support, such as conducting polymer, carbon-based catalysts, or a composite matrix composed of both. Objective: The main objective is to decrease the amount of precious metal-Pt required for financial considerations and to overcome the insufficient oxidation reactions’ rate of the fuel, which lead to the inevitable, naturally high, overpotential in fuel cell applications. Thereby, current research addresses the preparation of Pt, Pt-Ru, Pt-Ru-Pd and Pt-Ru-Mo metal nanoparticles modified by both polyaniline-multi-wall carbon nanotubes and polianiline-functionalized multi-wall carbon nanotubes composites and their activity in the methanol electro-oxidation. Methods: All of the composite surfaces were successfully prepared using electrochemical methodologies. A Citrate method was used for the preparation of metal nanoparticles. A comparative study was conducted on each stage of the investigation. The modified surfaces were characterized and analyzed by SEM, EDX, XRD, Raman, and TEM. Results: According to the spectroscopic measurements, all particles synthesized were detected as nanoscale. Binary and ternary catalysts supported on composite surfaces had higher activity and efficiency when compared to monometallic systems. Conclusion: The fabricated electrodes showed comparable catalytic activity, long-term stability, and productivity towards direct methanol fuel cell applications in acidic media.