摘要
通过洗涂法成功将La修饰的Cu-Mn尖晶石氧化物涂覆于蜂窝陶瓷上,并将其用于乙酸乙酯的催化分解。通过X射线衍射、X射线荧光、H_(2)程序升温还原、Brunauer-Emmett-Teller(BET)法、场发射扫描电镜对La修饰的Cu-Mn氧化物进行了表征。此外,研究了不同沉淀剂和稀土掺杂对催化剂结构和催化性能的影响。结果表明,以(NH_(4))_(2)CO_(3)为沉淀剂的CuMn_(2)O_(4)尖晶石可以形成较大的比表面积和合适的孔径,有利于乙酸乙酯的吸附,而稀土掺杂虽然没有明显改变催化剂的晶相结构,但其提高了催化剂的还原性并降低了催化分解的温度。对于乙酸乙酯的催化分解,在239℃、12500 h^(-1)的空速和1000×10^(-6)mol/cm^(3)的条件下,负载在蜂窝陶瓷上的稀土改性Cu-Mn氧化物显示出优异的催化性能,可使乙酸乙酯的转化率达到100%,且在连续反应1440 min后,乙酸乙酯的去除率仍为100%。
La-modified Cu-Mn spinel oxides were successfully coated on honeycomb ceramics by washcoating method and used for the catalytic decomposition of ethyl acetate.The La-modified Cu-Mn oxides were characterized by X-ray diffraction,X-ray fluorescence,H_(2) temperature-programmed reduction,Brunauer-Emmett-Teller(BET)method and field emission scanning electron microscopy.In addition,the effects of different precipitants and rare earth doping on the catalyst structure and catalytic performance were investigated.The results show that the CuMn_(2)O_(4)spinel with(NH_(4))_(2)CO_(3)as the precipitant can form a larger specific surface area and suitable pore size,which is beneficial to the adsorption of ethyl acetate.Although the rare earth doping does not significantly change the crystal phase structure of the catalyst,it improves the reducibility of the catalyst and lowers the temperature of catalytic decomposition.For the catalytic decomposition of ethyl acetate,rare earth-modified Cu-Mn oxides supported on honeycomb ceramics showed excellent catalytic performance at 239℃,a space velocity of 12500 h^(-1)and 1000×10^(-6)mol/cm^(3),which can make acetic acid The conversion rate of ethyl ester reached 100%.The removal rate of ethyl acetate was still 100%after 1440 min of continuous reaction.
作者
李利霞
王芳
蔡海军
LI Lixia;WANG Fang;CAI Haijun(Henan Jiyuan ecological environment monitoring center, Jiyuan, Henan 459000, China)
出处
《中国锰业》
2022年第3期20-26,共7页
China Manganese Industry
关键词
共沉淀
稀土改性
蜂窝陶瓷
催化氧化
Coprecipitation
rare earth modification
Honeycomb ceramics
Catalytic oxidation
