BaO对Pd/Al2O3催化性能的影响

以 Pd(C2 H3O2 ) 2 为前身 ,制备了系列 Ba O- Al2 O3复合氧化物负载钯的催化剂 .用质量滴定法 ,测定了复合载体的零电荷点 (pzc) .结果表明 ,体系的 pzc随 Ba O含量的增加而增大 ,在 5 %～ 10 %之间存在一拐点 ,并与XRD所测 Ba O在 Al2 O3上的单层分散阈值相对应 .复合载体在制备中发生固相反应 ,所生成的 Ba Al2 O4可以阻止 Al2 O3的相变 ,并极大地提高载体的热稳定性 ,其中 5 % Ba O的作用最为明显 .Ba O的引入 ,增强了 Pd/Al2 O3对 CO的氧化能力 ,同时 ,提高了其热稳定性

Effect of BaO on the Catalytic Properties of Pd/Al2O3

Supported palladium catalysts were prepared by impregnating method. The supports were characterized by BET method, X ray diffraction (XRD), and mass titration method. The basicities of supports increase with increasing BaO contents. The monolayer dispersion threshold, determined by measuring the point of zero charge with mass titration is consistent with the results of XRD analysis. BaO enhances the thermal stability of Al 2O 3 significantly owing to the formation of BaAl 2O 4. The introduction of BaO in creases the activity of Pd/Al 2O 3 for CO oxidation, and increases the thermostability of catalysts to some extent.