还原温度对CuO-ZnO-ZrO2催化剂的还原度及其低温CO氧化反应性能的影响

Effect of Reduction Temperature on Reduction Degree and Performance of CuO-ZnO-ZrO2 Catalyst for Carbon Monoxide Oxidation at Low Temperature

摘要:

采用还原热力学计算、H2-TIR、H2-TPR及活性评价等手段，考察了还原温度对CuO-ZnO-ZrO2催化剂的还原度和低温CO氧化反应性能的影响。研究发现，在CuO-ZnO体系中添加ZrO2，提高了CuO的分散度，使得活性组分CuO更容易还原，在相同还原条件下， 比 更容易进行。H2-TIR结果表明，随着还原活化温度的升高，还原耗氢量增大、还原峰出峰时间前移。通过H2的消耗量计算得到，随着还原温度的升高，还原度依次增大：0 %（100 ℃）< 45.7 %（140 ℃）< 77.3 %（160 ℃）< 86.2 %（200 ℃）。低温CO脱除性能评价表明，较优还原温度（160 ℃）下活化的催化剂具有较高的CO催化氧化活性，在100℃反应温度下，CO转化率达100 %；可将液相丙烯中微量的CO（10ppm）脱除低至0.02ppm，连续反应1500min，稳定性能良好。

Abstract:

Influence of reduction temperature on the reduction degree and performance of CuO-ZnO-ZrO2 catalyst for carbon monoxide oxidation at low temperature is investigated by means of reduction thermodynamic calculation, H2-TIR, H2-TPR and catalytic tests. It is found that the introduction of ZrO2 to CuO-ZnO improves the dispersion of active sites CuO with easy redox capacity and the transformation of valence state from Cu2 to Cu1 is easier than to Cu0. H2-TIR results indicate that the H2 consumption during reduction process increases, and the reduction peaks move forward with the increase of reduction temperature from 100℃ to 200℃. From the calculations by method of H2 consumption, the reduction degree of catalyst is found to increase with reduction temperature, in the order of 0% (100℃) < 45.7% (140℃) < 77.3% (160℃) < 86.2% (200℃). The catalyst activated at the optimal reduction temperature of 160℃ exhibits good catalytic performance, that shows 100% CO conversion in CO-probe oxidation at 100℃,and 0.02 ppm CO removal depth in the application of CO removal from liquid propylene.