| 在CeO2-ZrO2中加入La2O3对改善单Pd三效催化剂性能的作用 | |
| Effect of La2O3in CeO2-ZrO2 on Catalytic Performance of Pd-only Three-way Catalyst | |
| 摘要: 浸渍法制备了CeO2-ZrO2-La2O3复合氧化物，用XRD、热分析（TG-DTA，DSC）、BET表面积、H2-TPR等对合成样品进行表征，研究了La2O3的加入对CeO2-ZrO2和单钯Pd/CeO2-ZrO2/γ-Al2O3/蜂窝陶瓷催化剂性能和热稳定性的影响。结果表明，在CeO2-ZrO2-La2O3中，La的存在能促进CeO2-ZrO2固溶体的还原，提高贮氧能力；在Pd/CeO2-ZrO2/γ-Al2O3中加入La有利于提高催化剂的耐热稳定性，阻止γ-Al2O3在高温下的晶相转变，进一步稳定Al2O3的结构，保持其高的表面积。在贵金属Pd的负载量为1 g·L-1的条件下，测定了Pd/CeO2-ZrO2-La2O3/γ-Al2O3/蜂窝陶瓷催化剂对CO、C3H8和NOx的三效催化净化活性。结果表明，在Pd/CeO2-ZrO2/Al2O3/蜂窝陶瓷催化剂中加入La2O3后，能明显地改善催化剂的低温活性和三效催化性能，经1 000 ℃老化10 h后，CO、C3H8和NOx净化的起燃温度（T50）分别为330 ℃、350 ℃和380 ℃。 | |
| 关键词: γ -Al2O3 CeO2-ZrO2-La2O3固溶体 三效催化剂 La的作用 Pd催化剂 | |
| 基金项目: | |
| Abstract: The CeO2-ZrO2-La2O3mixed oxides were prepared by co-precipitation method and characterized by XRD, TG-DTA, TG-DSC, BET surface area and H2-TPR. The effects of La2O3addition on CeO2-ZrO2 and Pd-only/γ-Al2O3/ ceramic honeycomb’s catalytic performance and thermal stability were studied. The results show that the La2O3addition in CeO2-ZrO2 is beneficial to promote the reduction of CeO2-ZrO2 solid solution, to improve its oxygen storage capacity, to suppress transformation of γ-Al2O3into others, and further to increase the structure stability of alumina, thus keeping the high surface area of catalyst. The three-way catalytic activity of Pd/CeO2-ZrO2-La2O3/ γ-Al2O3/ ceramic honeycomb was measured for a simulated exhaust gas containing CO, C3H8, O2 and NOx when the loading of Pd was 1 g·L-1 on catalyst. It is found that the presence of La2O3can improve remarkably the low temperature catalytic activity and three-way catalytic performance of the catalyst. Over the Pd / CeO2-ZrO2 -La2O3/ γ-Al2O3/ ceramic honeycomb catalyst aged at 1 000 ℃ for 10 h, the initial light-off temperature (T50) for CO, C3H8 and NOx was 350 ℃, 355 ℃ and 380 ℃, respectively. | |
| Keywords: γ-Al2O3 CeO2-ZrO2-La2O3solid solution three-way catalyst effect of La | |
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| 蒋平平,卢冠忠,郭杨龙,郭 耘,王筠松,张顺海,王幸宜.在CeO2-ZrO2中加入La2O3对改善单Pd三效催化剂性能的作用[J].无机化学学报,2004,20(12):1390-1396. | |
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