Selective catalytic oxidation of carbon monoxide with carbon dioxide,water vapor and excess hydrogen on CuO-CeO_2 mixed oxide catalysts

摘要

A series of CuO-CeO_2 catalysts with Cu content in the range of 5-50 at.%(the atomic percent of Cu/(Cu + Ce))were prepared by co-precipitation method.The catalysts were tested for CO oxidation and selective CO oxidation with CO_2,H_2O and excess H_2.The catalysts were highly active in the CO oxidation and also active and remarkably selective in the selective oxidation.CO_2 and H_2O,however,decreased the catalyst activity;between CO_2 and H_2O,H_2O decreased the activity more than COj.Among the catalysts,the 10 at.% Cu catalyst outperformed all the other catalysts in the CO oxidation without CO_2 and H_2O in the feed,whereas the 20 at.% Cu exhibited the highest activity in the selective CO oxidation.This change in the optimum Cu content could be ascribed to the adverse effect of H_2O on the activity that was dependent on the Cu content of the catalysts.