摘要
以Al2O3为载体,采用沉积沉淀法制备了无铬环境友好型Cu-ZnO-MnOx/Al2O3催化剂,并用于α,α-二甲基苄醇氢解制异丙苯研究.利用X射线粉末衍射(XRD)、低温N2吸附、扫描电镜(SEM)、X荧光光谱仪(XRF)等表征及活性评价手段考察了沉淀pH值、沉淀温度、老化时间和焙烧温度对催化剂物化性质及催化性能的影响.试验结果表明,沉淀温度主要影响前驱体中各物相的转化速率;沉淀pH值和老化时间不仅影响前躯体中各物相的转变速度而且影响Cu2+、Zn2+的同晶取代速率;焙烧温度则主要影响前躯体的分解和催化剂的晶粒大小,前躯体中(Cu0.3Zn0.7)5(CO3)2(OH)6和(CuZn)2CO3(OH)2是CuO-ZnO固溶体的主要物相,而(Cu0.3Zn0.7)5(CO3)2(OH)6物相的形成有利于提高催化剂的稳定性.
Cu-ZnO-MnOx/Al2O3 catalyst was prepared by a deposition-precipitation method and used in hydrogenolysis of α,α-dimethyl-benzyl alcohol to cumene.Various techniques including： X-ray diffraction,N2 adsorption-desorption,scanning electron microscopy and XRF were employed for characterizing the physico-chemical properties of this kind of catalyst.The effects of synthesis conditions such as pH value,deposition temperature,aging time,and calcinations temperature on catalytic performance were studied in detail.The results indicating that the pH value and aging time mainly affected the the rate of phase changing as well as the rate of substitution between Cu2＋ and Zn2 ＋,the calcination temperature was affected the decomposition of precursor and the size of the catalyst.（Cu0.3Zn0.7）5（CO3）2（OH）6 and（CuZn）2（CO3）（OH）2 in the precursors were the vital phase in correspondence with the high activity of the catalyst.In addition,it seems that the CuO-ZnO solid-solution originating from the decomposition of（Cu0.3Zn0.7）5（CO3）2（OH）6 has higher catalytic activity than it counterpart originating from（CuZn）2CO3（OH）2.
出处
《分子催化》
EI
CAS
CSCD
北大核心
2010年第5期422-427,共6页
Journal of Molecular Catalysis(China)
基金
国家重大基础研究计划(973)项目(批准号:2009CB623502)
关键词
CU催化剂
制备条件
α
α-二甲基苄醇
催化氢解
Cu catalyst
α
α-dimethyl-benzyl alcohol
Synthesis conditions
Catalytic hydrogenolysis
