【作者】 吴伟；

【导师】 张密林；

【作者基本信息】 哈尔滨工程大学 ， 材料学， 2007， 博士

【摘要】 随着对新型聚酯材料PEN需求的日益增长,开发一步合成其单体原料2,6-DMN的方法以降低PEN生产成本显得尤为重要,高选择性催化材料的研制是一步法合成2,6-DMN的核心技术。本论文以萘（NAPH）与甲醇烷基化和2-甲基萘（2-MN）与1,2,4,5-四甲基苯（TeMB）转移烷基化合成2,6-二甲基萘（2,6-DMN）的高选择性环境友好型催化材料的设计、合成和催化性能改进为目标,研制出性能优异的HZSM-12分子筛择形催化材料和对2,6-DMN高选择性的系列氯铝酸盐类酸性离子液体催化材料,采用XRD、FT-IR、SEM、N₂吸附、²⁷AlNMR、NH₃-TPD、Py-IR和乙腈-IR等分析手段对这两类催化材料的结构和酸性进行了表征,考察了HZSM-12分子筛和氯铝酸盐类离子液体的合成条件对其结构、酸性和催化性能的影响。以HZSM-12分子筛为催化材料在固定床连续催化反应装置上优化出萘与甲醇烷基化合成2,6-DMN反应的适宜工艺条件,即反应温度为350℃,反应压力为4 MPa,质量空速（WHSV）为3 h^-1,萘:甲醇:1,2,4-三甲苯（TMB）的摩尔比为1:2:10。以氯铝酸盐类离子酸性液体为催化材料在釜式间歇反应器中优化得到2-MN和TeMB转移烷基化的适宜反应条件,即反应温度为20℃、2-MN:TeMB的摩尔比为1:1、反应时间为8 h,离子液体用量为32wt.%。分别采用离子交换、同晶置换、化学和水蒸气脱铝以及碱脱硅等方法对HZSM-12分子筛的表面酸性和孔结构进行了改性和调变。相对于Mg²⁺离子交换,La³⁺离子交换改性的HZSM-12具有更高的催化反应活性（萘的转化率）和2,6-DMN选择性及2,6-/2,7-DMN比,反应5 h后可分别达到46.4%,30.0%和2.0。镓同晶置换改性使HZSM-12分子筛的孔容增大,酸强度降低,产生了新的Lewis酸中心,有利于催化反应活性和2,6-DMN选择性的提高。相对于盐酸、柠檬酸等化学法和水热法脱铝,磺基水杨酸脱铝改性后HZSM-12分子筛的催化反应活性和2,6-DMN选择性均有所提高,反应5 h后分别为40.2%和29.3%。碱脱硅改性可使HZSM-12分子筛形成微孔-介孔结构,降低了其酸强度,提高了催化反应活性、2,6-DMN选择性以及2,6-/2,7-DMN比,分别为55.0%,30.6%和2.0,是一种有效的分子筛改性方法。制备了1-烷基-3-甲基咪唑氯铝酸盐（[C_nmim]Cl-xAlCl₃）、N-烷基吡啶氯铝酸盐（[C_nPy]Cl-xAlCl₃）和三乙铵氯铝酸盐（Et₃NHCl-xAlCl₃）离子液体催化材料。催化2-甲基萘转移烷基化合成2,6-DMN的反应结果表明,通过调节离子液体的阳离子结构、酸强度、改变反应条件可以控制烷基化反应深度,抑制2,6-DMN的异构化反应,提高2,6-DMN的选择性。在20℃、常压、2-MN/TeMB摩尔比为1.0、三氯化铝的摩尔分数x为0.71,离子液体用量32wt.%的条件下反应8 h,当以[C₄Py]Cl-xAICl₃为催化剂,2-MN转化率为22.7%时,2,6-DMN的选择性和2,6-/2,7-DMN比分别高达到80.5%和4.1;而以Et₃NHCl_-xAlCl₃为催化剂时,2,6-/2,7-DMN比仅为2.3,但2-MN转化率和2,6-DMN的收率最高,分别达到48.7%和1 8.5%;以[C₄mim]Cl_-xAlCl₃为催化剂时,2-MN转化率和2,6-DMN选择性分别为30.9%和68.2%,2,6-/2,7-DMN比为3.7。以混合甲基萘取代2-MN作为转移烷基化反应原料时,催化反应活性基本不变,2,6-DMN选择性略有降低。通过离子液体的循环使用,分析了失活原因,提出了氯铝酸盐类离子液体催化合成2,6-DMN的反应机理。更多还原

【Abstract】 With the increase of the more requirement for new polyester material-PEN, it is necessary to reduce the production cost of PEN by one-step preparation of its monomer-2,6-dimethylnaphthalene（2,6-DMN）. The development of the catalytic materials with high selectivity and high activity is the core technology for one-step synthesis process of 2,6-DMN.The HZSM-12 zeolite and series of chloroaluminate ion liquid catalytic materials with high selectivity for 2,6-DMN and high reaction activity were prepared for alkylation of naphthalene（NAPH） with methanol（ME） and transalkytion of 2-methylnaphthalene（2-MN） with 1,2,4,5- tetramethylbenzene （TeMB） to synthesize 2,6-DMN by design, synthesis and modification of catalytic properties for high selectivity and environmental friendly catalytic materials. The structure and acidity for two kinds of catalytic materials were analyzed and characterized by means of XRD, FT-IR, SEM, N₂ adsorption, ²⁷A1NMR, NH3-TPD, Py-IR and CH3CN-IR. The effects of synthesis conditions for HZSM-12 zeolite and chloroaluminate ion liquids on their structure, acidity and catalytic properties were investigated.On the continuous fixed-bed catalytic reaction equipment, the suitable reaction conditions such as temperature of 350℃, pressure of 4 MPa, weight hourly space veolicity （WHSV） of 3h^-1 and NAPH/ME/1,2,4- trimethylbenzene （TMB） ratio of 1/2/10 were achieved for alkylation of NAPH with ME to synthesize 2,6-DMN over HZSM-12 zeolite,In the bath kettle reactor, the suitable reaction conditions such as temperature of 20℃, 2-MN/TeMB ratio of 1.0, reaction time of 8 h and addition amount of catalyst of 32 wt.% were obtained for transalkylation of 2-MN with TeMB to synthesize 2,6-DMN over ion liquids.The surface acidity and pore structure of HZSM-12 zeolite were modified by ion exchange, isomorphous substitution, chemical and steamed dealumination and base desilication technologies. Compared to Mg²⁺ ion exchange modification, the catalytic activity （conversion of NAPH）,selectivity of 2,6-DMN and ratio of 2,6-/2,7-DMN for HZSM-12 zeolite modified by La³⁺ ion exchange get higher and respectively reach to 46.4%, 30.0% and 2.0 at 5 h. HZSM-12 zeolite modified by isomorphous substitution of gallium benefits for the rise of catalytic activity （conversion of NAPH）, selectivity of 2,6-DMN and ratio of 2,6- /2,7-DMN because of larger pore volume, lower acid strength and new Lewis acid site. Compared to the dealumination modification by HCl, citric acid and steam, the catalytic activity, selectivity of 2,6-DMN and ratio of 2,6- /2,7-DMN were improved and respectively reach to 40.2%, 29.3% at 5 h for HZSM-12 modified by the sulfosalicylic acid dealumination. The base desilication modification may form micro-mesopore structure in HZSM-12 zeolite to reduce its acid strength and get rise of the catalytic activity, selectivity of 2,6-DMN and ratio of 2,6-/2,7-DMN, respectively this is 55.0%, 30.6% and 2.0 at 5 h. It is a kind of effective modification method of zeolites.The ion liquid catalytic materials, such as 1-alkyl-3-methylimidazolium aluminum chloride（[C_nmim]Cl-xAlCl₃）,N-alkylpyrodium aluminum chloride （[C_nPy]Cl-xAlCl₃） and Et₃NHCl-xAlCl₃ were prepared. It was showed from results of catalytic transalkylation of 2-MN & TeMB to synthesize 2,6-DMN that the alkylation reaction progress and the isomerization of 2,6-DMN could be controlled, and selectivity of 2,6-DMN get rise via adjusting the structure of cations, acid strength and changing reaction conditions.When [C₄Py]Cl-xAlCl₃ was used for catalyst, the highest selectivity of 2,6-DMN and ratio of 2,6- /2,7-DMN were obtained and respectively reached to 80.5% and 4.1, and conversion of 2-MN was 22.7%. The highest conversion of 2-MN and yield of 2,6-DMN were achieved and respectively reached to 48.7% and 18.5%, but ratio of 2,6- /2,7-DMN only was 2.3 by using Et₃NHCl-xAlCl₃ as catalyst. The conversion of 2-MN, selectivity of 2,6-DMN, ratio of 2,6-/2,7-DMN respectively were 30.9%, 68.2% and 3.7 in catalytic transalkylation over[C₄mim]Cl-xAlCl₃.The reaction activity basically keep unchange and the selectivity of 2,6-DMN slightly decreased by using mixed methylnaphthalene instead of pure 2-MN as material of transalkylation.It was found that moisture in the system of reaction is main reason that leads to deactivation of ionic liquids in cycle utilization. The reaction mechanism of transalkylation reaction of 2-MN with TeMB catalyzed by chloroaluminate ionic liquids has been proposed.更多还原