ZrO_2相态对ZSM-5@ZrO_2催化剂物化性质及甲硫醇合成的影响

采用水热包覆法成功制备了ZSM-5@ZrO_2催化剂,研究了ZrO_2不同相态对催化剂物化性质和甲硫醇合成的影响。借助XRD、SEM、FTIR、Raman、BET和NH_3/CO_2-TPD等手段对催化剂结构性质进行了分析表征。结果表明,ZrO_2不同相态对催化剂物化性质和催化性能影响较大。以四方晶相t-ZrO_2制得ZSM-5@t-ZrO_2催化剂形成了均匀的包覆相结构和微-介孔结构(微孔比表面积114. 12 m^2/g、介孔比表面积125. 08 m2/g、总比表面积239. 2 m^2/g、总孔容0. 38 cm^3/g),同时具有酸碱特性(总酸量0. 071 mmol/g、总碱量0. 077 mmol/g)。在反应压力1. 0 MPa、H_2S/CH_3OH摩尔比2∶1、氮气流量90 m L/min、反应温度370℃条件下,催化剂表现出良好催化性能和反应寿命,CH_3OH转化率和CH_3SH选择性分别为92. 07%、90. 89%,催化寿命达20 h。

Effect of ZrO2 Phase State on the Physicochemical Properties of ZSM-5@ZrO2 and Its Catalytic Performance for Methanethiol Synthesis

The ZSM-5@ZrO 2 catalysts were prepared via hydrothermal coating method, and effect of ZrO 2 phase state on the physicochemical properties and catalytic performance for methanethiol synthesis of catalyst was investigated. These catalysts were extensively characterized by XRD, SEM, FTIR, Raman, BET and NH 3/CO 2-TPD techniques to investigate their structure properties. The results indicated that various ZrO 2 phase state posed significant impact on the physicochemical properties and catalytic performance for methanethiol synthesis of ZSM-5@ZrO 2 catalysts. The homogeneous continuous coating phase and hierarchical structure (microporous specific surface area of 114.12 m ^2/g, mesoporous specific surface area of 125.08 m ^2/g, total specific surface area of 239.2 m ^2/g, the total pore volume of 0.38 cm 3/g) with acidity (total amount of acid of 0.071 mmol/g) and basicity (total amount of base of 0.077 mmol/g ) were successfully obtained from tetragonal phase t-ZrO 2 in ZSM-5@t-ZrO 2 catalyst. The catalyst exhibited excellent catalytic performances, stability and reaction life with methanol conversion of 92.07%, methanethiol selectivity of 90.89%, and catalytic lifetime of 20 h under the conditions of reaction pressure of 1.0 MPa, reaction temperature of 370 ℃, H 2S/CH 3OH molar ratio of 2∶ 1, nitrogen flow rate of 90 mL/min.