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从Pd纳米粒子溶胶出发,采用一步沉淀法和浸渍法分别制备了0.5%(质量分数)Pd/Ce0.6Zr0.4-x Y x O2(x=0,0.03,0.05,0.1)负载型三效催化剂,考察了贵金属纳米粒子的负载方法以及Y的掺杂量对三效催化活性和水热稳定性的影响。结果表明,和浸渍法制备的催化剂相比,采用一步沉淀法制备的催化剂具有更高的三效催化活性。对于一步沉淀法制备的催化剂,Y的掺杂量对新鲜样品的三效催化活性影响不大,然而,900℃水热老化后,Y的掺杂量为0.05的Pd/Ce0.6Zr0.35Y0.05O2催化剂表现出最佳的催化活性,且其三效窗口也最为稳定。以上研究结果表明,一步沉淀法是一种从贵金属纳米溶胶出发制备纳米三效催化剂的有效方法,且在铈锆储氧材料中掺杂适量的Y元素可以进一步提高催化剂的三效催化活性和水热稳定性。
Starting from the Pd nanoparticle sol, a one-step precipitation method and a dipping method were respectively used to prepare 0.5% (mass fraction) Pd / Ce0.6Zr0.4-xY x O2 (x = 0,0.03,0.05,0.1) The effects of loading method of noble metal nanoparticles and doping amount of Y on the three-way catalytic activity and hydrothermal stability were investigated. The results show that the catalyst prepared by one-step precipitation method has higher three-way catalytic activity than the impregnated catalyst. For the catalyst prepared by the one-step precipitation method, the doping amount of Y has little effect on the three-way catalytic activity of the fresh sample. However, after the hydrothermal aging at 900 ° C, the doping amount of Y is 0.05 Pd / Ce0.6Zr0.35Y0. 05O2 catalyst showed the best catalytic activity, and its three-way window is the most stable. The above results show that the one-step precipitation method is an effective method for preparing nano-three-way catalyst from noble metal nano-sol, and the doping amount of Y element in the cerium-zirconium oxygen storage material can further improve the three-way catalytic activity of the catalyst and water Thermal stability.