摘要
从Pd纳米粒子出发制备了具有核壳结构的新型纳米Pd@SiO2/Ce0.4Zr0.6O2三效催化剂及作为参比的Pd/Ce0.4Zr0.6O2催化剂,采用X射线衍射、透射电子显微镜、氢气程序升温还原和氮气低温吸附-脱附等技术对催化剂的物化性质进行了表征,研究了Pd@SiO2/Ce0.4Zr0.6O2和Pd/Ce0.4Zr0.6O2催化剂的三效反应催化活性和热稳定性.结果表明,SiO2壳层可以抑制Pd粒子的团聚,同时还能抑制Pd物种的再分散,减少Pd的流失.具有核壳结构的纳米Pd@SiO2/Ce0.4Zr0.6O2催化剂具有更好的三效催化活性和更高的热稳定性.
A New type of Pd@SiO2/Ce0.4Zr0.6O2 three-way nanocatalyst with core-shell structure was prepared from the colloidal Pd nanoparticles. For comparison, the corresponding reference catalyst Pd/Ce0.4Zr0.6O2 was synthesized. The catalysts were characterized by powder X-ray diffraction（XRD）, transmission electron microscopy（TEM）, nitrogen gas adsorption-desorption and temperature programmed reduction by H2（H2-TPR）. The three-way catalytic activities and the thermal stabilities of the two kinds of catalysts with different structure were investigated. It was found that the silica shell could prevent the aggregation of Pd nanoparticles. At the same time, the silica could inhibit the redispersion of Pd species so that the loss of precious metal Pd was reduced. All results showed that the Pd@SiO2/Ce0.4Zr0.6O2 nanocatalyst with core-shell structure possessed good three-way catalytic activities and high thermal stabilities.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2013年第8期1936-1944,共9页
Chemical Journal of Chinese Universities
基金
国家稀土稀有金属新材料和产业化专项--高性能稀土基汽车尾气催化器研发及国V催化器产业化
北京市自然科学基金(批准号:2101002)
国家自然科学基金(批准号:21007002)
国家'八六三'计划项目(批准号:2011AA03A40)
北京市创新团队项目(批准号:PHR201107104)资助
关键词
核-壳结构
三效催化剂
钯
二氧化硅
热稳定性
Core-shell structure
Three-way catalyst
Palladium
Silica
Thermal stability
