制备方法对锶改性氧化铝的高温热稳定性的影响

γ-Al2O3是一种常用的催化剂载体,但对于许多高温反应体系,如汽车尾气催化净化,其热稳定性在很大程度上制约了汽车催化剂的活性和稳定性.

The Influence of Preparation Methods on the Thermal Stability of Alumina Modified by Strontium

The thermal stabilization mechanism of strontium and effect of preparation method on the thermal stability of Sr modified alumina and the stabilization effect of strontium species have been investigated by measuring the BET specific surface area and powder X ray diffraction. The results show that strontium species can stabilize the alumina at high temperature and the stabilization effect of the strontium species increases with the rise of strontium content, however, the overabundance of strontium species weakens its stabilization effect. The preparation method influences the thermal stability of alumina and stabilization effect of strontium. The thermal stability of Sr modified alumina prepared by sol gel method is superior to that of samples prepared by gelation and impregnation. At high temperature, it is probable that the dispersed strontium species instead of hexaaluminate stabilizes the alumina.