高性能Ce_(0.5)Zr_(0.5)O_2稀土储氧材料的制备及其负载的单Pd三效催化剂

以碳酸铵水溶液为沉淀剂,改变前驱体盐溶液的浓度,采用共沉淀法制得了一系列Ce0.5Zr0.5O2固溶体材料.以此系列材料为载体制备了负载型单Pd三效催化剂,并利用N2吸附-脱附、X射线衍射、储氧量测定和程序升温还原等技术对材料了进行表征.结果表明,所制Ce0.5Zr0.5O2材料具有优异的抗高温老化性能和氧化还原性能,且盐溶液的浓度对材料及其负载型Pd三效催化剂性能的影响较大.当盐溶液浓度为0.3mol/L时,制备材料的织构性能最佳,经1000oC老化5h后其比表面积和孔体积分别为53.0m2/g和0.17cm3/g.所制得的三效催化剂对CO,NO和C3H8具有低的起燃温度和完全转化温度,表现出最佳的催化性能,具有良好的应用前景.

Preperation of High Performance Ce0.5Zr0.5O2 Rare Earth Oxygen Storage Material and Its Supported Pd-Only Three-Way Catalyst

A series of Ce0.5Zr0.5O2 oxygen storage material samples were prepared by co-precipitation using ammonium carbonate as precipitant.The effect of the concentration of the salt solution on the performance of the target materials and its supported Pd-only catalyst was investigated.The samples were characterized by N2 adsorption,X-ray diffraction,oxygen storage capacity,and temperature-programmed reduction.The results showed that the prepared material exhibited high thermal stability and perfect redox properties.When the concentration of the salt solution was 0.3 mol/L,the obtained material presented the best textural properties with a surface area of 53.0 m2/g and pore volume of 0.17 cm3/g after calcination at 1000 oC for 5 h.The corresponding catalyst exhibited higher catalytic activity with relative low light-off and full conversion temperature,showing potential application in automotive catalysts.