CATALYTIC OXIDATION OF CARBON MONOXIDE PRESENT IN LOW CONCENTRATIONS

The oxidation of carbon monoxide present in low concentrations has been studied in the presence of the CuO–Al2O3 (1:1) catalyst using 1,000–10,000 p.p.m. of CO in air in the temperature range 120°–322 °C, and gas space velocities ranging from 8,000–16,000 hr−1. It was found that for the entire concentration range studied, the percentage of oxidation of CO at a given temperature was independent of its initial concentration and at temperatures above 200 °C, more than 95% of CO was removed by oxidation at all gas space velocities up to 16,000 hr−1. A simple first-order rate equation was found to fit the experimental data well. The presence of water vapor in the reactant gas was found to have no effect on the efficiency of the catalyst at temperatures above 225 °C. The possible practical utility of the above catalyst for the removal of carbon monoxide present in auto exhaust gases was tested using a six-cylinder Chevrolet engine run on leaded gasoline fuel. It was found that under all conditions of engine operation, more than 99% of carbon monoxide present in the exhaust gases was removed by catalytic oxidation when the initial temperature of the catalyst bed was kept at or above 220 °C.