(1. 陕西科技大学 化学与化工学院，西安 710021
2. 北京理工大学 爆炸灾难预防、控制国家重点实验室，北京 100081)
摘 要: 采用溶胶−凝胶法制备三效催化剂促进剂Ce0.6Zr0.4O2、Ce0.6Zr0.35Pr0.05O2−y和Ce0.6Zr0.4−xTbxO2−y(x=0.05, 0.10, 0.15)，将其作为水洗层的储氧组分。制备的三效催化剂的活性测试表明，在铈锆氧化物固溶体储氧材料中掺杂少量Pr和Tb，可降低三效催化剂对CO、C3H6和NO的起燃温度。以C3H6的转化率为水洗层氧缓冲能力的探针，实验发现，含储氧材料的水涂层在贫氧气氛中，起到氧缓冲的作用，提高C3H6的转化率。通过实验和理论推导得出表征三效催化剂氧缓冲能力大小的参数K。此方法简单可行，表征的结果与以起燃温度表征的三效催化剂氧化还原活性的实验结果相一致。
关键字: 氧缓冲能力；起燃温度；氧化铈基储氧材料；掺杂；三效催化剂
（1. College of Chemistry and Chemical Engineering, Shaanxi University of Science and Technology, Xi’an 710021, China;
2. State Key Laboratory of Prevention and Control of Explosion Disasters, Beijing Institute of Technology, Beijing 100081, China）
Abstract:The three-way catalysts (TWCs) promoters Ce0.6Zr0.4O2, Ce0.6Zr0.35Pr0.05O2-y and Ce0.6Zr0.4−xTbxO2−y(x=0.05, 0.10, 0.15) were prepared by sol-gel method, and the catalytic performance was measured for the fully formulated Pt, Rh and Pd TWCs (high ratio of Pd) containing this kind of promoters as the oxygen storage materials of washcoat. The results show that the introduction of Pr and Tb ions into ceria-zirconia solid solution can decrease the ligh-off temperature of fresh TWCs. C3H6 conversion was used as a probe to test the oxygen buffering capacity of washcoat. The washcoats play a role of oxygen storage and the TWCs containing ceria-based oxygen storage materials have higher conversion rate for C3H6 oxidation under the oxygen-deficient condition. Parameter K was put forward through theoretical analysis and test, which offers a method to characterize the oxygen buffering capacity of oxygen storage materials. This method is simple and feasible, and the parameter K coincides with the results of catalytic activity test.
Key words: oxygen buffering capacity; ligh-off temperature; ceria-based oxygen storage materials; doping; three-way catalyst
