Ru/ZrO_2-CeO_2催化剂催化湿式氧化乙酸和苯酚的研究

Catalytic Wet Air Oxidation of Acetic Acid and Phenol with Ru/ZrO_2-CeO_2 Catalysts

采用共沉淀法制备了ZrO2-CeO2颗粒载体,利用浸渍法制备了Ru/ZrO2-CeO2颗粒催化剂,采用BET、XRD、SEM、TEM等方法对其进行了结构表征,测定了其催化湿式氧化乙酸的活性,并以苯酚为模型物进行了动态试验.结果表明,Zr的添加抑制了CeO2晶粒的长大,增加了催化剂的抗热性能.当催化剂Zr、Ce摩尔比为1∶9,焙烧温度为300℃时催化剂活性最高,在200℃和4 MPa下,催化湿式氧化乙酸反应120 m in后,COD去除率可达99%.动态实验100 h内,苯酚与COD的去除率都保持在90%以上,催化剂具有很好的活性和稳定性.

Pelletized ZrO2-CeO2 support and Ru/ZrO2-CeO2 catalysts were prepared by coprecipitation and impregnation respectively. The catalysts were examined by BET, XRD, SEM and TEM, and were studied in the wet air oxidation （WET） of acetic acid. The dynamic experiment was carried out using phenol as model reaction. The results showed that adding Zr into CeO2 restrained the growth of crystal, enhanced the ability of catalyst resistant to thermal treatment. The most active catalyst of Ru/ZrO2-CeO2calcinated at the temperature of 300 ℃ was obtained with 1 ： 9 molar ratio of zirconium and cerium. At the reaction temperature of 200 ℃ and the total pressure of 4 MPa, COD removal of acetic acid solution with pelletized Ru/ZrO2-CeO2 catalyst reached 99% in 120 min. In the dynamic experiment using phenol as model, phenol and COD removal were all above 90% during reaction processes of 100 h. It was confirmed that the pelletized Ru/ZrO2-CeO2 catalyst had high activity and excellent stability.