采用柠檬酸 -乙醇络合溶胶 -凝胶法合成了两个单一相钙钛矿型稀土复合氧化物 La-Co O3和 La Fe O3并对其进行了结构 ,电阻率 ,比表面积 ,表面氧特性和 CO氧化催化活性比较研究 ,结果表明 ,它们有几乎相近的大比表面积 ,但它们的晶系不同 ,La Co O3属三方晶系 ,La Fe O3属正交晶系 ,La Co O3比 La Fe O3具有高的吸附氧量和导电性及 CO低温催化氧化活性 。
本文以葡萄糖溶胶—凝胶法合成了稀土钙钛矿型复合氧化物 L a Co0 .9Cu0 .1 O3,并对其进行了 XRD、BET、TPR表征和二甲苯催化氧化性能测试 ,同时与柠檬酸溶胶—凝胶法作了比较。结果表明 ,葡萄糖作为络合剂成胶和干胶容易 ,粒径较小 ,具有进一步降低 L a Co0 .9Cu0 .1 O3形成温度的作用 ,以葡萄糖作为络合剂在 70 0℃所制备的催化剂 L a Co0 .9Cu0 .1
A series of copper cobalt composite oxides with different composition were synthesized by solid phase reaction using citric acid as a complex agent, and characterized with XRD, BET and TPR. The effects of the copper/cobalt ratio on the crystal structure, specific surface area, reduction performance and catalytic activity of the catalyst for xylene combustion were studied. It was found that the catalytic activity of the catalyst has close relation with the copper/cobalt ratio. The interaction between copper and cobalt improved the specific surface area and reduction properties of the samples. The catalyst sample with n (Cu)/ n (Co)=1 has the largest specific surface area, the highest activity and the lowest reduction temperature. At the same time, the experimental results indicated that the spinel CuCo 2O 4 has high catalytic activity for xylene complete oxidation. The addition of opportune copper oxide promotes the CuCo 2O 4 dispersion on the composite oxide.
