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...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。展开更多
Pd/CeO2 catalysts with flower-like morphology were fabricated via an ultrasonic-assisted membrane reduction （UAMR） and hydrothermal methods. The catalysts were physically characterized and evaluated for three-way ca...Pd/CeO2 catalysts with flower-like morphology were fabricated via an ultrasonic-assisted membrane reduction （UAMR） and hydrothermal methods. The catalysts were physically characterized and evaluated for three-way catalytic activities versus tradi- tional Pd/CeO2 catalysts. Flower-like Pd/CeO2 catalysts exhibited a higher catalytic performance and better thermal stability than the Pd/CeO2 prepared by conventional impregnation. The flower-like Pd/CeO2 catalysts were constructed from 20-50 nm thick nanosheet petals. These petals were in turn constructed from 10 nm CeO2 nanoparticles that self-assembled into the flower-like morphology re- sulting in abundant pores in all directions. The Pd nanoparticles were anchored and dispersed on both the interior and surface of the pores and had minimal sintering. When these catalysts were aged, the structure and morphology of the catalysts remained unchanged with important industrial implications for this new type of material including improved catalytic performance and high thermal stabil- ity. Regardless of the Pd loading, both the fresh and aged Pd/CeO2 catalysts prepared by the UAMR-hydrothermal method exhibited better performance than the corresponding samples prepared by conventional impregnation means.展开更多
基金supported by the National Natural Science Foundation of China (21277009)the Funding Project for Academic Human Resources Development in Institutions of Higher Learning under the Jurisdiction of Beijing Municipality(PHR201107104)~~
基金supported by the National High Technology Research and Development Program (863 Program,2009AA063201)the Funding Project for Academic Human Resources Development in Institutions of Higher Learning Under the Jurisdiction of Beijing Municipality (PHR201107104)~~
文摘从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。
基金Project supported by National Natural Science Foundation of China (20877006, 20833011)Beijing Municipal Natural Science Foundation (2101002)+2 种基金the Funding Project for Academic Human Resources Development in Institutions of Higher Learning under the Jurisdiction of Beijing Municipality (PHR201107104, PHR200907105)National High Technology Research and Development Program (2011AA03A406)National Industrial Project of New Rare Earth Materials
文摘Pd/CeO2 catalysts with flower-like morphology were fabricated via an ultrasonic-assisted membrane reduction （UAMR） and hydrothermal methods. The catalysts were physically characterized and evaluated for three-way catalytic activities versus tradi- tional Pd/CeO2 catalysts. Flower-like Pd/CeO2 catalysts exhibited a higher catalytic performance and better thermal stability than the Pd/CeO2 prepared by conventional impregnation. The flower-like Pd/CeO2 catalysts were constructed from 20-50 nm thick nanosheet petals. These petals were in turn constructed from 10 nm CeO2 nanoparticles that self-assembled into the flower-like morphology re- sulting in abundant pores in all directions. The Pd nanoparticles were anchored and dispersed on both the interior and surface of the pores and had minimal sintering. When these catalysts were aged, the structure and morphology of the catalysts remained unchanged with important industrial implications for this new type of material including improved catalytic performance and high thermal stabil- ity. Regardless of the Pd loading, both the fresh and aged Pd/CeO2 catalysts prepared by the UAMR-hydrothermal method exhibited better performance than the corresponding samples prepared by conventional impregnation means.
