壳-核式RuO2-TiO2/CeO2-TiO2复合催化剂的制备及催化湿式氧化性能研究

以CeO2-TiO2为载体,通过化学沉积、纳米活性层包覆、纳米烧结的方法在其表面包覆了RuO2/TiO2纳米层,制备得壳-核式RuO2-TiO2/CeO2-TiO2复合催化剂。通过XRD、XPS、UV-Vis、BET、SEM、TEM等手段对催化剂进行了表征。结果表明:纳米层中的RuO2包覆在TiO2表面,也形成了一种壳-核式结构,TiO2粒子的粒径约15nm,其表面的RuO2厚度约4nm,包覆纳米层后催化剂的比表面积明显增大。以丁二酸为模拟废水,对催化剂的催化湿式氧化活性进行了测试,研究了反应温度、pH等因素对催化湿式氧化活性的影响。与浸渍法制备的催化剂相比,新催化剂催化湿式氧化丁二酸的活性显著提高。乙酸和丙烯酸是丁二酸降解的主要中间产物。

PREPARATION AND CATALYTIC WET OXIDATION PERFORMANCE OF RUO2-TiO2/CeO2-TiO2 CATALYSTS WITH SHELL-NUCLEUS STRUCTURE

A composite catalyst of RuO2-TiO2/CeO2-TiO2 with shell-nucleus structure was prepared with CeO2-TiO2 as carrier and through coating of chemical sedimentation and nanometer activated layer of RuO2/TiO2 by nano sintering method.The catalyst was charactisterized through XRD,XPS,UV-Vis,BET,SEM,TEM etc.The results showed that RuO2 covering the surface of TiO2 in nanometer layer also formed a shell-nucleus structure with TiO2 granular size of about 15nm;the RuO2 thickness of its surface was about 4nm;after covering the nanometer layer,the catalyst's surface area increased obviously.A determination was carried out for the catalyst's catalytic wet oxidation activity.The effect of reaction temperature,pH etc.factors on catalytic wet oxidation was studied.In comparion with the catalysts prepared by soaking method,the activity of catalytic wet oxidation succinic acid of the new calalyst rose obviously;acetatate acid and acrylic acid are main intermediate products of succinic acid degradation.