【摘要】 研究采用共沉淀水热回流法,在聚四氟乙烯反应器中合成系列铈锆固溶体储氧材料;研究水热回流时的pH值对合成铈锆固溶体储氧材料的影响。用XRD、低温N₂吸附-脱附和H₂-TPR等手段对合成样品的物化性能进行表征,结果表明,在研究的pH值范围内,控制水热回流时溶液的pH值为11时,合成铈锆固溶体的性能最佳,经600℃焙烧5h后,其比表面积最高可达91.1 m²/g,孔半径集中分布在3.9nm左右,总孔体积为0.22cm³/g;且其具有最低的还原温度,储氧量为309μmol/g。此外,经1 100℃焙烧5h后仍无晶相分离现象,说明其具有良好的热稳定性能。更多还原

【Abstract】 A series ceria-zirconia solid solution oxygen storage materials were successfully synthesized by coprecipitation-reflux method.The reflux treatment of freshly precipitated cerium-zirconium hydroxides was carried out in a teflon flask.Effect of the pH of the precipitated solution on the synthesis of ceria-zirconia solid solution oxygen storage materials was studied.The samples were characterized by X-ray diffraction,N₂ physical adsorption and hydrogen temperature programmed reduction.The results show that by controlling the pH of the precipitated solution at about 11,the obtained sample exhibited the best properties.After calcination at 600℃ for 5h,it not only has a high surface area approaching to 91.1m²/g,a narrow pore radius size distribution centered on around 3.9nm,and a pore volume of 0.22m³/g,but also has the lowest reducible temperature with the total oxygen storage capacity up to 309μmol/g.Furthermore,after calcination at 1 100 ℃ for 5h,the samples still have a single phase,which indicates its high thermal stability.更多还原