Synthesis and Characterization of Cu-MOF derived Cu@AC electrocatalyst for Oxygen Reduction Reaction /

Abstract

Metal Organic frameworks (MOFs) are dominant among the scientists over the other materials due to their high porosity, crystal structure, good conductivity and stability in various environments. This unique property makes them a promising material for many energy systems applications such as Hydrogen storage, low temperature fuel cells and Lithium ion batteries. In this study, biomass derived activated carbon (AC) was used to improve electrochemical properties of Cu-MOF. Dried leaves (Lantana) were activated with H3PO4 for preparation of AC. Cu-MOF was pyrolyzed with different ratios of AC in Argon (Ar) environment (1:1, 1:0.5, 1:0.25). These composite materials were examined by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), Thermal gravimetric analysis (TGA), Fourier Transform Infrared Spectroscopy (FTIR) and Brunauer-Emmett-Teller (BET). The synthesized catalyst was tested for its electro catalytic activity for Oxidation Reduction Reaction (ORR) in three electrode system by cyclic voltammetry (CV), Tafel Plot, Chronoamperometry and Electrochemical Impedance spectroscopy (EIS). The electrochemical parameters calculated by film coated GCE exhibit impact of activated carbon on oxidation reaction catalysed by Cu-MOF. The Composite1 (Cu@AC (1:1)) showed current density of 2.11mA/cm2 at an onset potential of 0.9V which is greater than the commercial Pt/C measured as 1.37mA/cm2 at onset potential of 0.86V. While other composites (Cu@AC (1:0.5) and Cu@AC (1:0.25)) showed almost equal and little lower performance respectively as compared to commercial Pt/C. The intensified stability and electrochemical activity is due to synergistic effect of MOF and AC composites.