摘要
以硝酸铈和硝酸锰为原料、NaOH为沉淀剂,采用共沉淀法制备了Ce_(1)Mn_(3)前驱体粉末,将其与纳米氧化铝胶干粉通过混捏煅烧制备了复合金属氧化物催化剂Ce_(1)Mn_(3-x)/γ-Al_(2)O_(3)(x为Ce_(1)Mn_(3)前驱体粉末质量,分别为1、3、5、7、9 g,原料总质量10 g)。采用XRD、BET和SEM对Ce_(1)Mn_(3-x)/γ-Al_(2)O_(3)进行了表征,通过固定床反应器考察其对气态低含量乙酸乙酯(体积分数0.1%)的催化降解性能,并探究了水蒸气对反应的影响和48 h催化稳定性。结果表明,γ-Al_(2)O_(3)的引入并没有改变Ce_(1)Mn_(3)物相。与Ce_(1)Mn_(3)相比,Ce_(1)Mn_(3-x)/γ-Al_(2)O_(3)的比表面积增大(由38.55 m^(2)/g增至60.03~204.79 m^(2)/g),介孔数量明显增加。Ce_(1)Mn_(3)氧化物结合在γ-Al_(2)O_(3)表面,暴露出的Ce_(1)Mn_(3)氧化物颗粒更加细小且分散。制备的Ce_(1)Mn_(3)-7/γ-Al_(2)O_(3)催化活性最高,在空速(GHSV)15000 mL/(g·h)条件下,乙酸乙酯降解率达到90%时的温度(T_(90))为164.5℃。载体γ-Al_(2)O_(3)和水蒸气的引入均有利于乙酸乙酯在低温下(<120℃)的降解,促进中间体乙酸和乙醇生成,导致最终T_(90)降低。在180℃、48 h、不含水蒸气的反应条件下,Ce_(1)Mn_(3)-7/γ-Al_(2)O_(3)催化剂能始终保持99%以上的乙酸乙酯降解率。
The composite metal oxide catalysts Ce_(1)Mn_(3-x)/γ-Al_(2)O_(3)(x is the mass of Ce_(1)Mn_(3) precursor powder,x=1,3,5,7 and 9 g,and total raw material mass is 10 g)were prepared from mixing and calcination of nano alumina gel powder and Ce_(1)Mn_(3) precursor,which was synthesized by co-precipitation method using cerium nitrate and manganese nitrate as raw materials,with NaOH as precipitant,and characterized by XRD,BET and SEM.The catalytic degradation performance of Ce_(1)Mn_(3-x)/γ-Al_(2)O_(3) on gaseous low content ethyl acetate(volume fraction 0.1%)was evaluated in a fixed bed reactor,while the effect of water vapour on the reaction and the 48 h catalytic stability were analyzed.The results showed that the introduction ofγ-Al_(2)O_(3) did not change the Ce_(1)Mn_(3) phase.Compared with those of Ce_(1)Mn_(3),the specific surface area of Ce_(1)Mn_(3-x)/γ-Al_(2)O_(3) increased from 38.55 m^(2)/g to 60.03~204.79 m^(2)/g,and the number of mesopores significantly increased.Ce_(1)Mn_(3) oxide was bound to the surface ofγ-Al_(2)O_(3),and the exposed Ce_(1)Mn_(3) oxide particles were smaller and more dispersed.The Ce_(1)Mn_(3)-7/γ-Al_(2)O_(3) obtained showed the highest catalytic activity.Under a space velocity(GHSV)of 15000 mL/(g·h),the degradation rate of ethyl acetate reached 90%at 164.5℃(T_(90)).The introduction of carrierγ-Al_(2)O_(3) and water vapor were beneficial to the degradation of ethyl acetate at low temperature(<120℃),promoting the generation of degradation intermediates acetic acid and ethanol,resulting in a decrease in the final T_(90).Under the conditions of 180℃,48 h and without water vapour,the Ce_(1)Mn_(3)-7/γ-Al_(2)O_(3) could consistently maintain a degradation rate of over 99%for ethyl acetate.
作者
孙哲恺
张智宏
杜晓刚
SUN Zhekai;ZHANG Zhihong;DU Xiaogang(School of Petrochemical Engineering,Changzhou University,Changzhou 213164,Jiangsu,China)
出处
《精细化工》
北大核心
2025年第6期1359-1365,共7页
Fine Chemicals
关键词
共沉淀法
混捏技术
γ-Al_(2)O_(3)
催化氧化
乙酸乙酯
环境保护
co-precipitation method
mixing and kneading technology
γ-Al_(2)O_(3)
catalytic oxidation
ethyl acetate
environmental protection
作者简介
孙哲恺(1998-),男,硕士生,E-mail:jacksun_98@163.com;联系人:张智宏(1966-),女,教授,E-mail:czhangzh@163.com。
