Development of a copper chromite catalyst for carbon monoxide automobile emission control

Copper-chromium catalysts employed for CO oxidation were found to be affected by composition and pretreatment parameters. CuCr₂O ₄ was more active than CuO only if prereduction was carried out and if metal concentration on alumina support was larger than 12 wt%. The presence of Cr with Cu in the oxide limited the extent of catalyst reduction leading also to less deactivation as compared to Cu on alumina. The presence of Cr also decreased an activity inhibition effected by water. A supported Cu-Cr catalyst used in an automobile ran with leaded petrol was deactivated by lead deposition. Deposits were mainly lead sulphate located on pellet periphery. Also, lead was preferentially distributed on the alumina instead of on the active metal-rich zones of the catalysts.