PdO/ZrO_2/γ-Al_2O_3/Al_2O_3-SiO_2纤维催化剂的制备及其催化燃烧性能研究

Preparation of PdO/ZrO_2/γ-Al_2O_3/Al_2O_3-SiO_2 Fiber Catalyst and Research on Its Catalytic Combustion Performance

制备了0.05wt%PdO/0.15wt%ZrO2/γ-Al2O3/Al2O3-SiO2纤维催化剂,考察了ZrO2对催化剂甲烷催化燃烧性能的影响。结果表明,当ZrO2的掺杂量为0.15wt%时催化剂活性最好,其甲烷完全转化温度为401℃。比表面积测定(BET)结果显示,加入γ-Al2O3极大地提高了催化剂的比表面积;氧气程序升温脱附(O2-TPD)实验结果表明,加入适量ZrO2,提高了活性相PdO的分解温度,从而提高了催化剂热稳定性。对所制备的催化剂进行了实用性能考察表明:0.05wt%PdO/γ-Al2O3/Al2O3-SiO2纤维催化剂使用50次(100h)后烟气中的CO浓度提升为首次使用时的2倍、燃烧温度也提高了44℃;而添加了0.15wt%ZrO2的催化剂的使用性能非常稳定、预测其具有长的使用寿命。

0.05 wt% PdO/ZrO2/γ-Al2O3/Al2O3-SiO2 fiber catalyst was developed and the influence on methane catalytic combustion performance by ZrO2 was investigated. The results indicated the catalyst was of the best reactivity when doped ZrO2 was by 0.15 mass percent, and the complete combustion temperature is about 401 ℃. Specific area can be increased greatly by loading γ-Al2O3, which was measured by BET. Results of oxygen temperature programming desorption demonstrated that decomposition temperature or thermal stability of active substance PdO was increased by adding proper amount of ZrO2. Service performance investigation of fiber catalysts indicated that CO concentration of exhaust air for the PdO catalyst without ZrO2 was changed from 30 ppm to 63 ppm for the first time and the fiftieth time, accordingly, combustion temperature changed from 425℃ to 469℃. Otherwise, with the PdO catalyst doped by ZrO2, CO concentration changed little, forecasting a longer lifespan.