Cu@Co NCNTs Cathode Catalyst Derived from ZIF-67 for ORR in PEMFC /

Abstract

This study is based on the activity of Cu and Co based MOF composites towards the electrochemical oxidation for oxidation reduction reactions for fuel cells. Co based MOF (ZIF-67) was prepared as reported and Cu based MOF (Cu-TPA) was prepared by hydrothermal method. The two composites were mixed solvothermally and were Pyrolysed in Ar atmosphere at 700°C. The characterization was done by the X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier Transform Infrared spectroscopy (FTIR) followed by Brunauer Emmett Teller analysis for porosity and surface area analysis. Through XRD, bimetallic incorporation was confirmed with in all 3 composite. The synthesized composites were studied for the electrochemical activity in ORR through cyclic voltammetry (CV), Electrochemical Impedance spectroscopy (EIS) and Chronoamperometry (CA). The results showed that the composite with 30 wt% Cu incorporated with 70 wt% ZIF-67 represented the best activity by giving a current density of 11.8 mA/cm2. The current density increased with decreasing quantity of Cu in composite 7.59 mA/cm2 and 1.32 mA/cm2 at scan rate of 100 mV for 50 wt% Cu- 50 wt% ZIF-67 composite and 70 wt% Cu- 30 wt% ZIF-67 composite respectively. The enhanced activity is attributed to the presence of high surface area and activity of ZIF-67.