Electrooxidation of selected organic molecules on Graphene based nanocomposites for fuel cell applications

Abstract

Exploring high performance electrocatalysts for the electrooxidation of small organic fuels like CH3OH, C2H5OH, HCOOH etc. is an extremely important concept in realzing fuel cells as convenient energy sources. In a typical fuel cell, supplied fuel molecules undergo electrooxidation on an anode catalyst (typically nanosized particles dispersed on conductive carbonaceous supports) to produce electrons and protons. Electrons thus produced are forced through an external circuit to generate current while protons formed are passed through a proton exchange membrane (PEM) and get reduced to water on a cathode catalyst with supplied oxygen and electrons travelled through the circuit thereby completing a cell reaction. By optimizing the chemical reduction methodologies nanoparticles with good extent of homogeneity can be fabricated on carbonaceous support and can be utilized as anode catalysts for the electrooxidation of fuel molecules like CH3OH, C2H5OH, HCOOH etc. To integrate the anode catalyst in a fuel cell device it is very important to study catalyst electrochemical activity for a particular electrochemical reaction in half-cell configurations by coating catalyst ink on to a glassy carbon (GC) rotating disk electrode (RDE) using cyclic voltammetry. From the electrochemical investigations electrochemical activity parameters like mass-specific activity, surface area-specific activity, onset potential etc. can be evaluated and can get information about the catalyst efficacies towards specified electrochemical reactions. newlineThe objective of the present work is largely focused on the development of high performance reduced graphene oxide (RGO)-supported electrocatalysts for important fuel cell reactions like formic acid oxidation reaction (FAOR), ethanol oxidation reaction (EOR) and methanol oxidation reaction (MOR). The RGO-supported electrocatalysts fabricated in the present research study are Pd-CeO2/RGO (for FAOR application), Pt-Pd/RGO (as an EOR electrocatalyst), Pd-Cu/RGO (for MOR application) and Pt-Ru/RGO-TiO2 (