石油学报(石油加工) ›› 2019, Vol. 35 ›› Issue (4): 766-774.doi: 10.3969/j.issn.1001-8719.2019.04.019

• 研究报道 • 上一篇    下一篇

ZSM-5/MgO质量比对复合催化剂物化性质及合成甲硫醇反应的影响

刘飘1,2,刘飞1,2,3,杨凯旭1,2,曹建新1,2,3   

  1. 1. 贵州大学 化学与化工学院, 贵州 贵阳 550025;
    2. 贵州省绿色化工与清洁能源技术重点实验室,贵州 贵阳 550025;
    3. 贵州省矿产资源高效利用与绿色化工技术特色重点实验室,550025

  • 收稿日期:2018-05-14 修回日期:2018-11-05 出版日期:2019-07-25 发布日期:2019-09-24
  • 通讯作者: 刘飞, 男,教授,博士,从事资源能源转化催化技术研究;E-mail:ce.feiliu@gzi.edu.cn; 曹建新,男,教授,博士,从事资源能源转化催化技术研究;E-mail:jxcao@gzu.edu.cn E-mail:ce.feiliu@gzu.edu.cn
  • 作者简介:第一作者:刘飘,男,硕士研究生,从事资源能源转化催化技术研究;E-mail: 2581295874@qq.com
  • 基金资助:
    国家自然科学基金项目(21666007)、贵州省百层次创新型人才专项(黔科合平台人才([2016]5655)、贵州省科技创新人才团队(黔科合平台人才([2018]5607)、贵州省科技计划项目(黔科合平台人才([2017]5788)

Effects of Mass Ratio of ZSM-5/MgO on the Physicochemical Properties and Catalytic Performance in the Synthesis of Methanethiol

LIU Piao1,2, LIU Fei1,2,3, YANG Kaixu1,2, CAO Jianxin1,2,3   

  1. 1. School of Chemistry and Chemical Engineering, Guizhou University, Guiyang 550025, China;
    2. Guizhou Key Laboratory for Green Chemical and Clean Energy Technology, Guiyang 550025, China;
    3. Guizhou Key Laboratory for Efficient Utilization of Mineral and Green Chemical Technology, Guiyang 550025, China
  • Received:2018-05-14 Revised:2018-11-05 Online:2019-07-25 Published:2019-09-24

摘要: 采用介孔碱性MgO对微孔酸性ZSM-5分子筛进行复合改性,利用液相沉淀包覆技术制备了ZSM-5/MgO复合催化剂,研究了ZSM-5与MgO质量比对复合催化剂物化性质和合成甲硫醇催化性能的影响。采用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、比表面积及孔隙分析仪(BET)和化学吸附分析仪(CO2/NH3-TPD)等手段对不同复合催化剂的晶相组成、微观形貌、孔结构及表面酸碱性进行分析表征。结果表明:ZSM-5/MgO质量比对ZSM-5/MgO复合催化剂的物化性质和催化性能影响较大。过高或过低ZSM-5/MgO质量比制得复合催化剂中MgO结晶度都有所降低,且未形成包覆相结构;ZSM-5/MgO质量比为1/3时制得复合催化剂形成了均匀包覆相结构和微介孔结构(总比表面积为162 m2/g,总孔体积0.46 cm3/g),同时具有酸碱特性;在反应压力1.0 MPa、反应温度370  ℃、H2S/CH3OH摩尔比2/1、N2流速80 mL/min、H2S流速4.9 mL/min反应条件下合成甲硫醇,复合催化剂表现出优越的催化性能、稳定性及寿命,CH3OH转化率、CH3SH选择性和CH3SH收率分别达到90.48%、90.04%和81.47%,催化剂寿命达到18 h。与单一ZSM-5分子筛相比,复合催化剂寿命延长了7 h,CH3SH收率提高了13.97百分点。

关键词: ZSM-5/MgO, 复合催化剂;质量比;甲硫醇合成;催化性能

Abstract: ZSM5/MgO composite catalysts were fabricated by using acidic microporous ZSM-5 molecular sieve and mesoporous alkaline MgO, based on liquidphase precipitation coating route. The effect of mass ratio of ZSM-5 to MgO on the physicochemical properties and their catalytic performance in the synthesis of methanethiol was investigated. These obtained composite catalysts were extensively characterized by the X-ray diffractometer (XRD), scanning electron microscope (SEM), specific surface area and pore analyzer (BET) and chemisorption analyzer (CO2/NH3-TPD) techniques to investigate their crystalline property, morphology, pore structure and surface acidity-basicity, respectively. Results indicate that various mass ratios of ZSM-5 to MgO pose significant impact on the physicochemical properties and their catalytic performance. The crystallinity and content of MgO in composite catalyst is greatly affected by the ZSM-5/MgO mass ratio. As ZSM-5/MgO mass ratio of 1/3, the homogeneously continuous coating phase and hierarchical structure (total specific surface area of 162 m2/g, the total pore volume of 0.46 cm3/g) with acidity and basicity are successfully obtained, which exhibits excellent catalytic performances, stability and reaction lifetime, with methanol conversion of 90.48%, methanethiol selectivity of 90.04%, methanethiol yield of 81.47%, and catalyst lifetime of 18 h under the conditions of reaction pressure of 1.0 MPa, reaction temperature of 370 ℃, H2S/CH3OH molar ratio of 2/1, nitrogen flow rate of 80 mL/min and hydrogen sulfide flow rate of 4.9 mL/min. Compared with ZSM-5 molecular sieve, the reaction lifetime of the composite catalyst is extended by 7 h and the yield of methanethiol is increased by 13.97 percentage.

Key words: ZSM-5/MgO, composite catalyst, mass ratio, methanethiol synthesis; catalytic performance