(1. 陜西科技大學(xué) 化學(xué)與化工學(xué)院，西安 710021
2. 北京理工大學(xué) 爆炸災(zāi)難預(yù)防、控制國家重點(diǎn)實(shí)驗(yàn)室，北京 100081)
摘 要: 采用溶膠−凝膠法制備三效催化劑促進(jìn)劑Ce0.6Zr0.4O2、Ce0.6Zr0.35Pr0.05O2−y和Ce0.6Zr0.4−xTbxO2−y(x=0.05, 0.10, 0.15)，將其作為水洗層的儲(chǔ)氧組分。制備的三效催化劑的活性測(cè)試表明，在鈰鋯氧化物固溶體儲(chǔ)氧材料中摻雜少量Pr和Tb，可降低三效催化劑對(duì)CO、C3H6和NO的起燃溫度。以C3H6的轉(zhuǎn)化率為水洗層氧緩沖能力的探針，實(shí)驗(yàn)發(fā)現(xiàn)，含儲(chǔ)氧材料的水涂層在貧氧氣氛中，起到氧緩沖的作用，提高C3H6的轉(zhuǎn)化率。通過實(shí)驗(yàn)和理論推導(dǎo)得出表征三效催化劑氧緩沖能力大小的參數(shù)K。此方法簡單可行，表征的結(jié)果與以起燃溫度表征的三效催化劑氧化還原活性的實(shí)驗(yàn)結(jié)果相一致。
關(guān)鍵字: 氧緩沖能力；起燃溫度；氧化鈰基儲(chǔ)氧材料；摻雜；三效催化劑
（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
