Maximum % conversion of CO over CoFeZnNiGa was found out to be 99.8% at 175 0 Cat 10,000 h -1 GHSV. The rate of CO oxidation reaction was also calculated at various temperatures from the slope of the curve (W/F) with the molar conversion of CO (Figure ). Here, W is the weight of the catalyst, and F is the flow rate of CO in sccm . Rates of the reaction w.r.t weight at temperatures 313K, 348K, 373K were found out to be 2.38, 5.26, 6.39 µmol/g/sec, respectively. Activation energy was found to be 3.761 kJ/mol, which is the lowest among the materials well-known in literature (Figure ). Cleary, the HEA catalyst is highly active for the CO oxidation reaction.