摘要
采用柠檬酸燃烧法制备MgO-CeO2(10%,质量分数)复合载体和CeO2单载体,用浸渍还原法以水合肼为还原剂制备负载型Cu2O催化剂,以环己醇脱氢制环己酮为探针反应,考察其脱氢性能;采用TPR,XRD,CO2-TPD,环己醇/环己酮-TPD及BET等手段对催化剂进行表征。实验发现,与商品MgO和CeO2为载体的催化剂相比,复合载体负载的催化剂Cu2O/MgO-CeO2(10%)表现出更高的环己醇脱氢活性。这是由于复合载体负载的催化剂中CeO2的存在提高了催化剂的比表面积,有利于活性组分的分散;增强了催化剂中弱碱位的强度并增加了弱碱中心的数量,改变了催化剂的表面吸附能力,因而对环己醇脱氢具有更高的催化活性。3种催化剂都呈碱性,是其具有高环己酮选择性的原因之一。
MgO-CeO2 （10%, mass fraction） and CeO2 were prepared by amorphous citrate method, catalysts Cu2O/MgO-CeO2 （ 10% ） , Cu20/CeO2, and Cu2O/MgO were prepared by chemical reduction combined with impregnation method. Dehydrogenation of cyclohexanol to cyclohexanone was selected as probe reaction to study their catalytic property. The samples were characterized by H2 temperature programmed reduction （H2-TPR）, X-ray diffraction （XRD）, CO2 temperature programmed desorption （CO2-TPD） , cyclohexanol TPD, cyclohexanone TPD and BET. The results showed that Cu2O/MgO-CeO2 exhibited higher catalytic activities than Cu2O/CeO2 and Cu2O/MgO. The reason might be that CeO2 increased the surface area of Cu2O/MgO which was beneficial to the dispersion of the active components. In addition, it also enhanced the strength and number of weak basic sites, and changed the intensity of adsorption sites over the surface of CuEO/MgO. All the catalysts showed high selectivity for cyclohexanone because of their alkalescence.
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2009年第2期252-257,共6页
Chinese Journal of Rare Metals
基金
国家自然科学基金(20863006)
江西省自然科学基金(0620042)
江西省教育厅科技项目(GJJ09078)资助
