Synthesis of Ni/Cu MOF and its rGO composites for Methanol Oxidation in Direct Methanol Fuel Cell

Abstract

Fuel cells seek attention with each passing day due to its significant characteristics like no moving part and energy production but we are also facing challenge due to the use of Pt, Pd, Ru and Rh as conventional catalysts as these metals are rare and expensive also produce poisonous intermediates and limit reaction due to slow kinetics. To deal with these challenges, there is a need of efficient, cost effective and readily available catalyst to use in fuel cell. In this research work a novel bimetallic Ni/Cu MOF has been developed for methanol oxidation reaction in direct methanol fuel cell. The bimetallic MOF has been synthesized by using two linkers (Benzene dicarboxylic acid (BDC) & Pyrazine) along with its composites with different amount of reduced graphene oxide (1wt% rGO-Ni/Cu MOF, 2wt% rGO-Ni/Cu MOF, 3wt% rGO-Ni/Cu MOF, 4wt% rGO-Ni/Cu MOF, 5wt% rGO-Ni/Cu MOF and 8wt% rGO-Ni/Cu MOF) through a hydrothermal method which is characterized by multiple significant techniques like XRD, SEM, EDX and FTIR for the sake of successful synthesis and investigation of their structural and morphological properties. The prepared series of material was later used for electrochemical oxidation reaction of methanol studies. The electrochemical activity of synthesized catalyst was tested by using a reliable technique of cyclic voltammetry (CV) in a basic medium on modified glassy carbon electrode (GCE) by using three electrode system. The electrochemical activity depicts that increasing concentration of rGO “Enhanced the activity of catalyst for MOR”. The catalyzed oxidation reaction of methanol by Ni/Cu MOF and rGO-Ni/Cu MOF composites give a superlative current density with peak value of 437.28 mA/cm2 at 0.9V potential at 50 mV/s scan rate. Electrochemical impedance spectroscopy results also showed lowest charge transfer Rct for 5wt% rGO-Ni/Cu MOF and this catalyst showed stability upto 52% over a period of 3600 seconds tested by chronoamperometry. This activity makes it a promising nominee for electrolysis.