Cu改性SAPO-11分子筛催化萘和甲醇甲基化反应的研究

Study on Methylation of Naphthalene with Methanol over SAPO-11 Zeolites Modified by Cu

分别采用水热合成法和浸渍法对SAPO-11分子筛进行Cu改性.通过X射线衍射(XRD)、扫描电镜(SEM)、NH_3-程序升温脱附(NH_3-TPD)、H_2-程序升温还原(H_2-TPR)、^(29)Si固体核磁共振(^(29)SiMAS NMR)以及N_2吸附-脱附(N_2adsorption-desorption)等表征手段对改性前后SAPO-11分子筛的结构、酸性进行表征,并研究了改性后分子筛催化合成2,6-二甲基萘反应性能的影响规律.结果表明,经水热合成法进行Cu改性的SAPO-11分子筛结晶度升高,酸中心数量增加,比表面积和孔体积上升,从而使萘的转化率、2,6-二甲基萘的选择性、2,6-二甲基萘与2,7-二甲基萘的比值及2,6-二甲基萘的收率提高.

In this paper, SAPO-11 zeolite catalyst has been modified by Cu through the use of hydrothermal syn- thetic method and impregnation method, respectively. The structure and acid property of SAPO-11 before and after modification were characterized by XRD, SEM, NH3-TPD, TPR, zgsi MAS NMR and N2 absorption-desorption, and the influence of the catalytic performance of SAPO-11 zeolite modified on the synthesis of 2,6-dimethylnaphtha-lene （2,6-DMN） was also studied. Results showed that SAPO-11 zeolite was modified by Cu through hydrothermal synthetic method, the crystallinity of zeolite was increased, the amount of acidic sites, surface area and pore volume were increased. As a result, the naphthalene conversion, 2,6-DMN selectivity, the ratio of 2,6-DMN to 2,7- DMN and 2,6-DMN yield increased significantly.