焙烧气氛对MnAPO-36分子筛催化性能的影响  

Effect of Calcination Atmosphere on the Catalytic Performance of MnAPO-36 Molecular Sieve

作　　者：邓莹[1] 陈斌[1] 吴剑[1] 袁霞[1] 罗和安[1] 

机构地区：[1]湘潭大学化工学院,湖南湘潭411105

出　　处：《石油化工》2011年第3期247-250,共4页Petrochemical Technology

基　　金：国家自然科学基金;中国石油化工股份有限公司联合资助重点项目(20736009)

摘　　要：对以拟薄水铝石、磷酸、四水合醋酸锰为原料,三正丙胺为模板剂,采用原位水热法合成的MnAPO-36分子筛原粉,分别在氧气、空气和氮气气氛下进行了焙烧。NH3-TPD表征结果表明,氧气和空气气氛下焙烧的试样具有强酸中心,且氧气气氛下焙烧的试样酸量更大;XPS分析结果表明,氧气和空气气氛下焙烧的试样中存在MnⅡ和MnⅢ,而氮气气氛下焙烧的试样中只有MnⅡ。环己烷氧化探针反应结果表明,在无溶剂体系下,催化剂用量0.60 g时,30 g环己烷在135℃、氧气压力1.60 MPa下反应3 h,氧气气氛下焙烧的MnAPO-36分子筛催化剂具有相对较好的催化性能,环己烷的转化率为11.85%,环己醇、环己酮、环己基过氧化物和己二酸的总选择性为70.10%。MnAPO-36 molecular sieve was hydrothermally synthesized in situ from pseudo-boehmite, phosphoric acid and tetrahydrate manganese acetate with tripropylamine as templating agent and was calcined in O2, air and N2 atmosphere separately. The calcined MnAPO-36 molecular sieves were characterized by means of NH3-TPD and XPS. The NH3-TPD results showed that the MnAPO-36 molecular sieves calcined in 02 and air possessed strong acid sites, and the quantity of the acid sites in the MnAPO-36 calcined in 02 was more than that calcined in air. The XPS results revealed that there were both MnⅡ and MnⅢ ions in the MnAPO-36 molecular sieves calcined in 02 and air,but there was only MnⅡ ions in the MnAPO-36 molecular sieve calcined in N2. The activity of the MnAPO-36 calcined in 02 in cyclohexane oxidation, the probe reaction, was the highest. Under the optimal conditions of 135 ℃, O2 pressure 1.60 MPa ,3 h,0. 60 g MnAPO-36 calcined in 02 as catalyst, cyclohexane 30 g and solvent-free, the cyclohexane conversion was 11.85 %, and the total selectivity to cyclohexanol, cyclohexanone, cyclohexylhydroperoxide and adipic acid was 70. 10%.

关 键 词：MnAPO-36分子筛催化剂 焙烧气氛 环己烷氧化 

分 类 号：TQ426.64[化学工程]