Pt_HSO_3_bvim_HSO_4_SiO_2双功能催化剂制备及其催化性能研
负载型对甲苯磺酸催化剂的制备及其催化双酯化反应研究
负载型对甲苯磺酸催化剂的制备及其催化双酯化反应研究白林;陈洁;王代莲【摘要】以二氧化钛、二氧化硅、硅胶、活性炭、活性氧化铝等固体材料为载体分别负载对甲苯磺酸,硬脂酸和乙二醇双酯化反应为模版,筛选出高活性的负载型催化剂.实验结果表明,活性氧化铝负载对甲苯磺酸催化酯化反应活性最高.在该酯化反应条件下,探讨了不同负载方法、负载量、催化剂用量和催化剂重复使用对酯化反应的影响.当活性氧化铝负载对甲苯磺酸催化剂负载量为19.7％,催化剂用量为0.2g,反应温度130℃时,反应2h,产物产率可达97.1％.该负载型催化剂是一种选择性高、催化性能良好的环境友好型催化剂,而且重复使用效果好.【期刊名称】《甘肃高师学报》【年(卷),期】2017(022)003【总页数】4页(P16-19)【关键词】活性氧化铝;对甲苯磺酸;硬脂酸;乙二醇;乙二醇双硬脂酸酯【作者】白林;陈洁;王代莲【作者单位】兰州城市学院绿色化学实验与教学研究所,甘肃兰州730070;兰州城市学院绿色化学实验与教学研究所,甘肃兰州730070;兰州城市学院绿色化学实验与教学研究所,甘肃兰州730070【正文语种】中文【中图分类】O625.5;TQ206对甲苯磺酸（p-toluenesulfonic acid，TsOH），是一种白色针状或粉末状结晶，可溶于水、醇、醚和其他极性溶剂，极易潮解，易使木材、棉织物脱水而碳化.常见的有对甲苯磺酸一水合物（TsOH·H2O）和四水合物（TsOH·4H2O）.对甲苯磺酸是一种无氧化性的有机酸，被广泛用作催化剂，具备浓硫酸的许多优点，活性高、不腐蚀设备、污染小，碳化作用比浓硫酸弱，操作工艺简单.因此，对甲苯磺酸是替代浓硫酸作为有机反应催化剂的最佳选择.用对甲苯磺酸催化羧酸与正丁醇双酯化反应已有报道[1，2]，该催化剂具有反应时间短、酯化率高、反应条件温和、便于操作等特点.但反应结束后，催化剂溶解在产品或废液中无法收回，导致产物要经过中和、水洗、干燥等工艺，后续处理工艺复杂.所以将活性催化剂负（固）载到另一种载体上，制成负载型催化剂符合绿色化学的发展要求.负载型催化剂相对于均相催化剂，具有稳定性好、能够重复利用、操作简便等优点，在绿色催化中占有重要的地位.负（固）载型催化剂的载体材料主要是无机载体，目前已被广泛应用的有活性炭、SiO2、TiO2、MCM-41分子筛、硅藻土、介孔材料、离子交换树脂等，这些载体共同的特点是有较高的比表面积、有活性官能团及规则的孔道等[3].负（固）载型催化剂的制备方法主要有吸附法、浸渍法、水热分散法、溶胶-凝胶法、接枝法等.负载对甲苯磺酸催化酯化反应的载体大多采用活性炭[4-7]，也有硅胶[8]、硅藻土[9]、MCM-41[10]、SBA-15[11]为载体的报道.活性炭作为载体价廉易得，但易脱色使产物颜色加深.而MCM-41、SBA-15载体材料需要制备.针对目前均相催化体系稳定性差、回收难、污染大的问题，将对甲苯磺酸负载到TiO2、SiO2、活性C、硅胶、活性氧化铝等价廉商品化的载体上制成载体催化剂，运用硬脂酸与乙二醇双酯化反应进行催化活性筛选，探索负载对甲苯磺酸催化剂的最佳制备方法、负载量，催化剂的用量和催化剂重复使用效率.2.1 实验原理以硬脂酸和乙二醇为原料，在负载对甲苯磺酸为催化剂作用下合成乙二醇双硬脂酸酯.化学反应式如下：2.2 仪器与试剂仪器：DF-101B集热式恒温磁力搅拌器（浙江省乐清市乐成电器厂）；Sartorius 电子天平（德国赛多利斯公司），分度值为0.1mg；ZK-82A型真空干燥箱；SHB-Ⅲ循环水式真空泵（西安禾普生物科技有限公司）；WRS-1A数字熔点测定仪（上海物理光学仪器厂），温度未校正；Nicolet 5700红外光谱仪（美国Thermo Nicolet公司，KBr压片）.试剂：对甲苯磺酸，硬脂酸，乙二醇，二氧化钛，二氧化硅，硅胶，活性氧化铝（ø3-7mm，上海分子筛厂），活性炭（粒状），氢氧化钠，盐酸，乙醇（95%）为国产分析纯或化学纯试剂，使用前均未进一步处理.2.3 载体催化剂的制备2.3.1 载体的预处理活性炭，用蒸馏水把粉末清洗干净，烘干后把颗粒活性炭在120℃下活化2h.硅胶、二氧化钛、二氧化硅、活性氧化铝，在110℃下干燥4h.2.3.2 催化剂制备称取5g预处理的催化剂载体，加入到20mL质量分数为30%的对甲苯磺酸溶液中，在100～110℃的油浴中搅拌，直至溶液中水分自然蒸干，然后在140℃下烘干至恒重.2.4 实验方法在50mL圆底烧瓶中按照n（硬脂酸）∶n（乙二醇）为1∶3.5的量依次加入硬脂酸、乙二醇，催化剂用量为3%（以占硬脂酸物质的量计）混合均匀，用装有回流冷凝装置的恒温磁力搅拌器加热搅拌，控制反应温度在130～135℃，反应2h.待反应结束后，趁热倒出溶液，并冷却.向烧瓶内加入少许氢氧化钠溶液溶解残余的硬脂酸，合并产物，在其中滴加稀盐酸至酸性，置于冰水中静置后硬脂酸酯析出.将所得硬脂酸酯抽滤，干燥，称重，计算产率.粗产品用95%乙醇重结晶、干燥后测定熔点，并用红外光谱表征结构.2.5 产物结构表征产物结构表征通过熔点测定和红外光谱仪进行结构分析.用数字熔点测定仪测定三次平均值为62.1～62.5℃，与文献[12]一致.其红外光谱图：2942～ 2792cm-1为C-H伸缩振动峰；1750～1735cm-1为 C=O的酯羰基伸缩振动峰；1280，1262，1163cm-1为C-O伸缩振动峰；708cm-1为(CH2）n，n>4平面摇摆振动.图中无-OH的伸缩振动峰，说明白色片状产物为乙二醇双硬脂酸酯.为了用比较少的实验次数全面考察各种因素对实验的影响，采用控制单一变量因素的方法对各因素进行探讨，如不同的载体催化剂、催化剂负载量、催化剂用量、催化剂重复利用等.3.1 负载型对甲苯磺酸催化剂制备方法的选择用三种方法制备负载型催化剂（以活性炭为例）：方法一是将一定浓度的对甲苯磺酸通过浸渍法使其负载到活性炭上，但实际上制备的载体催化剂负载量小，催化剂活性并无明显增加；方法二是将两者的混合物置于高于室温的环境中使分子的热运动加快，通过搅拌增大两者的接触面积和分子间的碰撞机会，使得活性组分能充分地负载到活性炭上，此法制得的负载催化剂的催化活性较方法一有所增加；方法三是将两者的混合物加热搅拌使水分蒸干恒重，相同浓度下对甲苯磺酸的负载量最高.这是由于活性组分对甲苯磺酸溶于水，载体与溶液呈两相，最终会达到吸附平衡.方法三避免了对甲苯磺酸的流失，活性组分也能更深入地进入载体的孔径内.因此，选择方法三制备载体催化剂.3.2 不同载体催化剂对双酯化产率及产品质量的影响分别选用活性炭、二氧化硅、二氧化钛、硅胶、活性氧化铝负载的对甲苯磺酸催化剂作为双酯化反应催化剂，以酯化产物的外观及产率作为判断催化剂效果的依据.按照2.4实验方法，结果如表1所示.从表1中可知，在其它条件相同载体不同的情况下，使用活性氧化铝负载对甲苯磺酸催化剂的产率与酯化产物的外观均优于其它载体.故以活性氧化铝负载对甲苯磺酸催化剂作为双酯化反应的最佳催化剂.3.3 催化剂负载量对双酯化产率的影响按1∶3.5取硬脂酸、乙二醇混合均匀，活性氧化铝负载对甲苯磺酸催化剂用量为3%（以占硬脂酸物质的量计），在110～120℃下，用装有冷凝回流装置的集热式恒温磁力搅拌器加热搅拌，反应时间为2h，结果如表2所示.从表2中可知,当活性氧化铝负载对甲苯磺酸催化剂负载量为19.7%时，产率最高，继续增加催化剂负载量产率反而降低.说明活性氧化铝负载对甲苯磺酸催化剂的催化活性与其酸度之间有一定的关系，随着负载催化剂负载量的增大，其催化活性增大.合成乙二醇双硬脂酸酯适宜的催化剂负载量为19.7%.3.4 催化剂用量对双酯化产率的影响按照2.4实验方法，考察负载量为19.7%的负载催化剂的用量对产物产率的影响，实验结果如表3所示.从表3中可知,当催化剂用量在0.2g时，产率最高达到97.1%，继续增加催化剂用量时产率反而降低，说明在一定范围内增加催化剂的用量有助于反应的正向进行，产率会随着催化剂的增加而增加，但是超出范围后，产率反而会随着催化剂的用量的增加有所降低.因此，从合成效率考虑，催化剂的最佳用量为0.2g.3.5 催化剂重复利用对双酯化产率的影响用负载量为19.7%的负载型对甲苯磺酸作为催化剂，用量为0.2g，其他条件、后处理同2.4.用保留在圆底烧瓶内的载体催化剂重复实验，实验结果见表4.由表4可以看出，制备的活性氧化铝负载对甲苯磺酸催化剂重复使用效果好.随着重复使用次数的增多，产率逐渐减小，负载对甲苯磺酸催化剂至少可以使用5次. 通过对各种不同催化剂载体的筛选，确定了活性氧化铝负载对甲苯磺酸为双酯化反应的适宜催化剂，并对催化剂的负载量、催化剂用量、催化剂的重复利用等影响因素进行了反复研究.负载对甲苯磺酸催化剂的催化活性与其酸度间具有一定的关系，随着负载量的增加，其催化活性也随之增大.当负载量为19.7%，在优化合成条件下，乙二醇双硬脂酸酯产率达到97.1%.负载型对甲苯磺酸催化剂既具备了均相酸催化剂的高活性、高选择性，克服了均相酸催化剂难分离、难回收、环境污染等问题，又可重复使用、反应条件温和、操作方便，是复合型催化剂的发展方向.【相关文献】[1]王兰芝，张景涛，林进.对甲苯磺酸催化合成癸二酸二丁酯的研究[J].化学试剂，2000，22（5）：311，292.[2]熊文高，俞善信，刘淑云.对甲苯磺酸催化合成邻苯二甲酸二丁酯[J].甘肃教育学院学报（自然科学版），2000，14（4）：37-39.[3]陈奠宇，吴正兴.固载型杂多酸催化剂研究新进展[J].应用化工，2006，35（10）:802-804.[4]韦国兵，江国防.活性炭固载对甲苯磺酸催化合成三羟甲基三丙烯酸酯[J].益阳师专学报，2002，19（3）：36-38.[5]訾俊峰，朱蕾.活性炭负载对甲苯磺酸催化合成癸二酸二正己酯[J].精细石油化工，2006，23（3）: 1-2.[6]白云飞，郑嘉明，张水英，等.活性炭负载对甲苯磺酸催化合成二甲基丙烯酸丁二醇酯[J].精细化工中间体，2006，36（5）：63-66.[7]郑帼，刘成林，吴波，等.活性炭负载对甲苯磺酸催化合成三羟甲基丙烷油酸酯[J].天津工业大学学报，2016，35（2）：52-55.[8]梁红冬，梁亚梁.硅胶负载对甲苯磺酸催化合成苯甲酸乙酯[J].日用化学工业，2012，42（6）：443-445.[9]梁红冬，吴健文.负载型对甲苯磺酸催化合成乙二醇硬脂酸单酯[J].精细化工中间体，2008，38（5）：58-61.[10]常胡，孙士淇，孟小雷，等.MCM-41负载对甲苯磺酸催化合成柠檬酸异辛酯[J].西北师范大学学报（自然科学版），2016，52（1）:62-67.[11]孙慧，邓启刚，田志茗.SBA-15负载对甲苯磺酸催化合成乙酸正丁酯[J].化工时刊，2006，20（11）：30-32.[12]崔萍，刘榛榛.乙二醇硬脂酸酯的合成[J].应用化工，2005，34（9）：550-551.。
ZIF-67衍生物微纳米花状Co3O4催化剂的制备及其OER催化性能研究
Hans Journal of Chemical Engineering and Technology 化学工程与技术, 2020, 10(2), 111-118Published Online March 2020 in Hans. /journal/hjcethttps:///10.12677/hjcet.2020.102016Preparation of ZIF-67 DerivativeMicro-Nano Flower-Like Co3O4 Catalystand Its OER Catalytic PerformanceShunzheng Ren, Lijuan Feng, Shuo Yao*College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao ShandongReceived: Mar. 2nd, 2020; accepted: Mar. 16th, 2020; published: Mar. 23rd, 2020AbstractUsing ZIF-67 as a precursor, micro-nano flower-like ZIF-67(f) was obtained based on the morpho-logical evolution of ZIF-67 based on ion-assisted solvothermal conditions, and micro-nano flow-ers-like Co3O4(f) was prepared in an air atmosphere by heat treatment. Electron microscope (SEM), transmission electron microscope (TEM), X-ray diffractometer (XRD), Fourier infrared spectro-meter (FT-IR), and gas adsorption instrument (BET) were used to characterize the morphology and structure of the material. The electrochemical performance of the material was tested using an electrochemical workstation, and the oxygen evolution reaction (OER) performance of the cat-alyst prepared at different temperatures was discussed. The results show that the electrocatalytic performance of the prepared flower-like Co3O4(f) is greatly improved compared with commercial Co3O4 and Co3O4(r). The micro-nano flower-like Co3O4(f) material prepared by calcination at 450˚C has the most excellent electrocatalytic performance. Its overpotential at a current density of 10 mA∙cm−2 is 390 mV, and the Tafel slope is 60 mV∙dec−1.KeywordsElectrocatalysts, MOFs, Co3O4, Oxygen Evolution Reaction, ZIF-67ZIF-67衍生物微纳米花状Co3O4催化剂的制备及其OER催化性能研究任顺政，冯丽娟，姚硕*中国海洋大学化学化工学院，山东青岛*通讯作者。
211064108_PtSn
化工进展Chemical Industry and Engineering Progress2023 年第 42 卷第 3 期PtSn/MgAl 2O 4-sheet 催化剂的制备及其PDH 反应性能张孟旭，王红琴，李金，安霓虹，戴云生，钱颖，沈亚峰（昆明贵金属研究所，稀贵金属综合利用新技术国家重点实验室，云南 昆明 650106）摘要：近年来，因为页岩气大规模开采的成功可以为丙烷脱氢制丙烯（PDH ）工艺提供大量廉价的丙烷，丙烷脱氢制丙烯已成为最有前途和最具吸引力的丙烯生产技术。
目前工业上丙烷脱氢主要采用的是负载型PtSn/Al 2O 3催化剂。
然而在丙烷脱氢高温反应中，PtSn 纳米粒子易烧结和积炭使催化剂遭受严重的失活。
为了解决上述问题，本文合成了片状的MgAl 2O 4尖晶石载体负载PtSn 金属纳米粒子，制备了PtSn/MgAl 2O 4-sheet 催化剂。
该催化剂具有较大的孔径，有利于PDH 反应中反应物的吸附和产物的脱附，提高了催化剂的活性同时降低了积炭含量。
同时片状的MgAl 2O 4尖晶石载体的（111）面与PtSn 纳米颗粒存在着强的相互作用，阻止了PtSn 纳米颗粒在高温反应中的烧结。
在丙烷脱氢反应中，丙烷的转化率达到了43.2%，丙烯的选择性达到了95.0%，失活速率仅为0.008h −1，其性能优于商用的PtSn/Al 2O 3催化剂。
关键词：丙烷脱氢；铂锡催化剂；形貌控制；丙烯；镁铝尖晶石中图分类号：TQ426.82 文献标志码：A 文章编号：1000-6613（2023）03-1365-08Preparation of PtSn/MgAl 2O 4-sheet catalyst and its PDH reactionperformanceZHANG Mengxu ，WANG Hongqin ，LI Jin ，AN Nihong ，DAI Yunsheng ，QIAN Yin ，SHEN Yafeng(State Key Laboratory of Advanced Technologies for Comprehensive Utilization of Platinum Metals, Kunming Institute ofPrecious Metals, Kunming 650106, Yunnan, China)Abstract: In recent years, propane dehydrogenation to propylene (PDH) has become the most promising and attractive propylene production technology because the successful large-scale exploitation of shale gas can provide a large amount of cheap propane. Currently, supported PtSn/Al 2O 3 catalysts are mainly used for propane dehydrogenation in industry. In the high temperature reaction of propane dehydrogenation, PtSn nanoparticles are prone to sintering and coke deposition, which causes severe catalyst deactivation. To solve the above problems, we synthesized PtSn/MgAl 2O 4-Sheet catalyst by using MgAl 2O 4-Sheet spinel as support. The catalyst had a large pore size, which was favorable for the adsorption of reactants and the desorption of products in the PDH reaction, and thus improves the activity of the catalyst and reduced the content of coke. Meanwhile, the (111) plane of the MgAl 2O 4 spinel support had a strong interaction with the PtSn nanoparticles, which prevented the sintering of PtSn nanoparticles in the high temperature reaction. In the propane dehydrogenation reaction with the prepared catalyst, the conversion of propane reached 43.2%, the selectivity of propylene reached 95.0%, and the deactivation研究开发DOI ：10.16085/j.issn.1000-6613.2022-0919收稿日期：2022-05-17；修改稿日期：2022-07-19。
卡斯特构型催化剂
卡斯特构型催化剂是一种有机硅行业重要的催化剂，由含二乙烯基的二硅氧烷衍生而来，分子式为C24H54O3Pt2Si6。
这种配位化合物广泛用于氢化硅烷化反应，具有以下优点：
与过氧化物体系相比，卡斯特催化剂具有更优的硫化加成温度、无腐蚀性酸性副产物产生以及无过氧化物降解副产物等特点。
与Speier催化剂硫化体系相比，卡斯特催化剂能适用于在不同溶剂中反应，具有更高的反应活性、更稳定的催化剂以及更不易泛黑等特点，并且适用于更广泛的反应温度。
此外，卡斯特催化剂是一种无色固体，结构比较复杂，一般被认为是零价铂的烯烃类混合物。
这种催化剂最早由卡斯特合成并研究，故得名。
如需更多关于“卡斯特构型催化剂”的信息，建议咨询相关科研人员。
H3PW12O40-TiO2／SiO2的制备及光催化性能
中 图分 类号 ：０ ４ ． ６ ６３ ３
文献 标识码 ： Ａ
文 章编 号 ：１０ －２ ８ （ ０ ７ ０ － １３ ０ ０７ ６３ ２０ ）３ ０ １－ ４
Ｐｒ ｐ ｒ ｔ ｎ ａ ｄ Ｐｈ ｔ ｃ ｔ ｌｔ ｏ ｅ ｔ ｓ ｏ Ｗ ｌ Ｏ４ 一Ｔ Ｏ２ Ｓｉ ｅ ａ ａ ｉ ｎ ｏ ｏ ａ ａｙ ｉ Ｐｒ ｐ ｒｅ ｆＨ３Ｐ ２ ０ ｏ ｃ ｉ ｉ ／ Ｏ２
王 珩 ， 孙 晓君
（ 哈尔 滨理 工大学 化学 与环境工程学院 ， 黑龙 江 哈 尔滨 １０４ ） ５００
摘
要 ：以硅 胶 为 载 体 ， 用 浸 渍 法 制 备 了 Ｈ Ｐ ２ 柏 一ＴＯ ／ ｉ ２催 化 剂． 用 Ｉ Ｔ 采 ３ Ｗｌ ０ ｉ ２ＳＯ 利 Ｒ、 Ｇ—
Ｄ Ａ Ｘ Ｄ Ｘ Ｓ对其结构进行表征． Ｔ 、Ｒ 、Ｐ 研究结果表明， 催化剂 中的活性组分二氧化钛 为锐钛矿型 ， 磷 钨 酸仍 保持 其 Ｋ ｇｉ ｅｇ ｎ结构 的基本 骨 架 ， 氧化 钛 及磷 钨 酸 二 者 均与 载 体之 间存 在 着化 学作 用 ． 二 通
维普资讯
第 １ ２卷
第 ３期
哈 尔 滨 理 工 大 学 学 报
Ｊ ０ＵＲＮＡＬ ＨＡＲＢＩ Ｎ ＵＮＩ Ｖ．Ｓ Ｉ Ｃ ．＆ Ｔ Ｈ． ＥＣ
Ｖ０ ＿ ２ Ｎｏ ３ ｌ１ ．
２０ ０ ７年 ６月
Ｊｎ ， ０ ７ ｕ ． ２ ０
Ｈ３Ｗ１ ４ 一 ｉ ／ ｉ 制备 及 光 催化 性 能 Ｐ ２ ０ Ｔ Ｏ２ ＳＯ２的 Ｏ
过对 染料 罗丹 明 Ｂ的超 声 光催化 降解研 究发 现 ， ４ Ｈ Ｐ ２ 柏的 ＴＯ 含 ｇ ３Ｗ１ ０ ｉ２溶胶 浸 渍在 １ｇｉ２ 的 １ＳＯ 上 催化 效果 最佳 ， Ｈ Ｐ ２ 柏可 明显提 高 ＴＯ 超声 光催化 降解 罗丹 明 Ｂ的 降解 率． 且 Ｗ。 ０ ｉ２
超声辅助制备酸碱双功能CaO_HMCM-22分子筛催化剂
2014年10月 CIESC Journal ·3924·October 2014第65卷 第10期 化 工 学 报 V ol.65 No.10超声辅助制备酸碱双功能CaO /HMCM -22分子筛催化剂王俊格1，梁金花2，孙守飞1，张文飞1，任晓乾1，姜岷2（1南京工业大学化学化工学院，江苏 南京 210009；2南京工业大学生物与制药工程学院，江苏 南京 210009） 摘要：采用超声浸渍法制备了一系列CaO 改性的HMCM-22分子筛催化剂，使用XRD 、N 2物理吸附-脱附、SEM 、FT-IR 、NH 3-TPD 及CO 2-TPD 等技术对催化剂物化性质进行了表征。
结果发现在超声作用下经CaO 改性后MCM-22分子筛的结构没有发生变化；超声空化作用降低了催化剂晶粒之间的团聚，促进了CaO 在分子筛表面的分散，增加了可接触的催化活性位；随着CaO 负载量的增加，催化剂上碱强度和碱量显著增加，而强酸含量明显减少，弱酸酸位有所增加。
对催化剂在Knoevenagel 缩合反应中的催化性能研究表明：与传统浸渍法相比，超声浸渍法所制备催化剂的催化活性明显较高，在优化的超声条件下反应2 h 苯甲醛转化率即可达88.3%。
催化剂CaO/HMCM-22的催化性能优于HMCM-22和CaO/NaMCM-22，对Knoevenagel 缩合反应体现出明显的酸碱协同催化作用。
超声法制备的催化剂重复使用性能显著提升，经过5次重复使用后苯甲醛转化率仍保持在65%以上。
关键词：超声浸渍；氧化钙；酸碱双功能；Knoevenagel 缩合反应；催化剂；沸石 DOI ：10.3969/j.issn.0438-1157.2014.10.024中图分类号：O 643.3 文献标志码：A文章编号：0438—1157（2014）10—3924—07Preparation of CaO/HMCM-22 zeolite catalyst with acid-base bifunction withultrasonic assistanceWANG Junge 1，LIANG Jinhua 2，SUN Shoufei 1，ZHANG Wenfei 1，REN Xiaoqian 1，JIANG Min 2(1School of Chemistry and Chemical Engineering , Nanjing Tech University , Nanjing 210009, Jiangsu , China ；2School of Biotechnologyand Pharmaceutical Engineering , Nanjing Tech University , Nanjing 210009, Jiangsu , China )Abstract: CaO/HMCM-22 zeolite catalysts were prepared by ultrasonic impregnation and characterized by XRD, N 2 physical adsorption-desorption, SEM, FT-IR, NH 3-TPD and CO 2-TPD. The structure of MCM-22 zeolite still remained after CaO modification with ultrasonic assistance. Ultrasonic cavitation could reduce the agglomeration between particles, improve the dispersion of CaO on the surface of zeolite and increase the accessible catalytic active sites. By increasing CaO loading, the strength and content of base increased, while the strength of strong acid decreased significantly and the amount of weak acidic sites increased slightly. Knoevenagel condensation reactions were conducted over the synthesized catalysts. The strategy developed here showed excellent catalytic performance for this reaction compared with the conventional impregnation method and the conversion of benzaldehyde reached 88.3% under optimal ultrasonic irradiation within 2 h reaction. The catalytic performance of CaO/HMCM-22 was better than that of HMCM-22 and CaO/NaMCM-22, resulting in good catalytic activity for Knoevenagel condensation reactions and obvious acid-base synergetic effects. The reusability of the synthesized2014-03-收到初稿，102014-06-收到修改稿。
甲烷二氧化碳重整制氢
Research ArticleNi/SiO2Catalyst Prepared with Nickel NitratePrecursor for Combination of CO2Reforming andPartial Oxidation of Methane:Characterization and Deactivation Mechanism InvestigationSufang He,1Lei Zhang,2Suyun He,2Liuye Mo,3Xiaoming Zheng,3Hua Wang,1and Yongming Luo21Research Center for Analysis and Measurement,Kunming University of Science and Technology,Kunming650093,China2Faculty of Environmental Science and Engineering,Kunming University of Science and Technology,Kunming650500,China3Institute of Catalysis,Zhejiang University,Key Lab of Applied Chemistry of Zhejiang Province,Hangzhou310028,ChinaCorrespondence should be addressed to Y ongming Luo;environcatalysis222@Received5August2014;Revised6January2015;Accepted6January2015Academic Editor:Mohamed BououdinaCopyright©2015Sufang He et al.This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use,distribution,and reproduction in any medium,provided the original work is properly cited.The performance of Ni/SiO2catalyst in the process of combination of CO2reforming and partial oxidation of methane to produce syngas was studied.The Ni/SiO2catalysts were prepared by using incipient wetness impregnation method with nickel nitrate as a precursor and characterized by FT-IR,TG-DTA,UV-Raman,XRD,TEM,and H2-TPR.The metal nickel particles with the average size of37.5nm were highly dispersed over the catalyst,while the interaction between nickel particles and SiO2support is relatively weak.The weak NiO-SiO2interaction disappeared after repeating oxidation-reduction-oxidation in the fluidized bed reactor at 700∘C,which resulted in the sintering of metal nickel particles.As a result,a rapid deactivation of the Ni/SiO2catalysts was observed in2.5h reaction on stream.1.IntroductionThe Ni-based catalyst has recently attracted considerable attention due to the plentiful resources of nickel,as well as its low cost and good catalytic performance comparable to those of noble metals for many catalytic reactions,such as hydrogenation of olefins and aromatics[1],methane reforming[2],and water-gas shift reaction[3].Therefore,Ni-based catalyst is believed to be the most appropriate catalyst applied in the industrial process[4–6].It is generally accepted that the catalytic performance of Ni-based catalyst is closely related to several parameters,including the properties of support,preparation method,and active phase precursor employed.Support plays an important role in determining the performance of Ni-based catalyst.Generally,a support with high surface areas is very necessary since it is effective in increasing Ni dispersion and improving thermal stability, hence not only providing more catalytically active sites,but also decreasing the deactivation over time of the catalysts due to sintering and migration effects[7,8].For its good thermostability,availability,and relative high specific surface area,SiO2support was widely used for preparing Ni-based catalyst[9].In particular,spherical silica is successfully used as a catalyst support in fluidized bed reactor due to its high mechanical strength.The method of catalyst preparation is another key param-eter which needs to be optimized because it will result in different structural and textural properties of Ni-based catalyst.Therefore,numerous methods,including precipi-tation,homogeneous deposition-precipitation,and sol-gel techniques,have been developed to enhance the performance of Ni-based catalyst[10–18].However,allthe above method-ologies mentioned are too complex or expensive to scaleHindawi Publishing Corporation Journal of NanomaterialsVolume 2015, Article ID 659402, 8 pages /10.1155/2015/659402up in industry.The incipient wetness impregnation(IWI) is one of the most extensively used method[19–23]due to its simplicity in practical execution on both laboratory and industrial scales,in addition to its facility in controlling the loading amount of the active ingredient.In addition,the choice of the precursor salt is also crucial since it determines whether the Ni-based catalyst will be prepared successfully or not.As an efficient precursor,two terms must be met:firstly,high solubility is desirable because the precursor concentration in the impregnation solution must be high[24];secondly,the ability to be decomposed during calcinations is prerequisite since the precursor must be fully transformed into oxide particles without leaving side species that may modify the properties of the support [24].As a result,owing to its commercial availability and low cost,as well as its high solubility in water and effortless decomposition at moderate temperatures,nickel nitrate is the precursor most often used in the preparation of Ni-based catalyst[23,24].In this paper,Ni/SiO2catalyst was prepared by incipient wetness impregnation(IWI)with nickel nitrate as precursor and tested in the process of combination of CO2reforming and partial oxidation of methane(CRPOM)to produce syngas.TG-DTA,HR-TEM,IR,UV-Raman,XRD,and H2-TPR were employed to characterize the Ni/SiO2catalysts in detail to reveal the relationship between synthesis,properties, and catalytic performances as well as to investigate the causes of deactivation.2.Experimental Section2.1.Catalyst Preparation.The Ni/SiO2catalysts were pre-pared with IWI using nickel nitrate as precursor according to our previous works[21,22].The SiO2was commer-cially obtained(S BET=498.8m2/g,Nanjing Tianyi Inorganic Chemical Factory).Prior to use,the SiO2was pretreated with5%HNO3aqueous solution for48h and then washed with deionized water until the filtrate was neutrality.The size of SiO2was selected between60and80mesh.It was then impregnated with an aqueous solution of nickel nitrate. The obtained sample was dried overnight at100∘C and subsequently calcined in air at700∘C for4h.Unless otherwise stated,the loading of Ni was3wt%,and the calcination temperature was700∘C.The Ni/SiO2catalyst was designated as3NiSN.2.2.Catalytic Reaction.The catalytic reaction was performed in a fluidized-bed reactor that was comprised of a quartz tube (I.D.=20mm,H=750mm)under atmospheric pressure at700∘C.Prior to reaction,2mL of catalyst was reduced at700∘C for60min under a flow of pure hydrogen at atmospheric pressure with a flow rate of50mL/min.A reactant gas stream that consisted of CH4,CO2,and O2,with a molar ratio of1/0.4/0.3,was used with a gas hourly space velocity(GHSV)of9000h−1.The feed gas was controlled by mass flow controllers.The effluent gas cooled in an ice trap was analyzed with an online gas chromatograph that was equipped with a packed column(TDX-01)and a thermal conductivity detector.Under our reaction conditions,the oxygen in the feed gas was completely consumed in all cases.2.3.Catalyst Characterization.FTIR spectra were measured using a Nicolet560spectrometer equipped with a MCT detector.The samples were tabletted to thin discs with KBr.Thermogravimetric analysis(TGA)and differential ther-mal analysis(DTA)were performed on a PERKIN ELMER-TAC7/DX with a heating rate of10∘C/min under oxygen (99.99%,20mL/min).The samples were pretreated with oxygen flow at383K for1h.UV-Raman spectra were carried out with a Jobin Yvon LabRam-HR800instrument,using325.0nm Ar+laser radi-ation.The excitation laser was focused down into a round spot approximately2μm in diameter.The resolution was 4cm−1and1000scans were recorded for every spectrum.The catalysts were ground to particle diameters<150μm before analysis.X-ray powder diffraction(XRD)patterns of samples were obtained with an automated power X-ray diffractometer (Rigku-D/max-2550/PC,Japan)equipped with a computer for data acquisition and analysis,using Cu Kαradiation, at40kV and300mA.The reduced samples were priorly reduced at700∘C for1h and cooled to room temperature in hydrogen atmosphere,but the fresh samples were used directly after calcined in air at700∘C for4h.All the samples were ground to fine powder in an agate mortar before XRD measurements.Transmission electron microscopy(TEM)images were recorded on a Philips-FEI transmission electron microscope (Tecnai G2F30S-Twin,Netherlands),operating at300kV. Samples were mounted on a copper grid-supported carbon film by placing a few droplets of ultrasonically dispersed suspension of samples in ethanol on the grid,followed by drying at ambient conditions.H2-temperature-programmed reduction(H2-TPR) experiments were performed in a fixed-bed reactor(I.D.= 4mm).50mg samples were used and reduced under a stream of5%H2/N2(20mL/min)from50∘C to800∘C with a ramp of7∘C/min.Hydrogen consumption of the TPR was detected by a TCD and its signal was transmitted to a personal computer.The experiments for reduction-oxidation cycle(redox) performance were performed as follows.The catalysts were pretreated with H2flow at700∘C for1h and then were cooled down to room temperature and reoxidized in O2at different temperature for1h.The reoxidized samples were then performed by H2-TPR experiments as above.3.Results and Discussion3.1.Catalytic Activity Measurements.The catalytic perfor-mance of Ni/SiO2was shown in Figure1.A rapid deactivation was detected for the3NiSN,and the corresponding conver-sion of CH4(X CH4)decreased from∼58%to∼25%within 1.5h reaction on stream.In order to investigate the causes of deactivation,the3NiSN catalyst was characterized by TG-DTA,HR-TEM,IR,UV-Raman,XRD,and H2-TPR in detail.Time on stream (h)60555045403530252015C o n v e r s i o n o f C H 4(%)Figure 1:CH 4conversion versus time on 3NiSN catalyst for combination of CO 2reforming and partial oxidation of methane to produce syngas (reaction temperature:700∘C,CH 4/CO 2/O 2=1/0.4/0.3,and GHSV =9000h −1).Wavenumber (nm)Figure 2:FT-IR spectra of 3NiSN (dried at 100∘C)and nickel nitrate (Ni(NO 3)2).3.2.Catalyst Characterization Results3.2.1.FT-IR Analysis.The FT-IR spectra of 3NiSN before cal-cination and Ni(NO 3)2precursor were illustrated in Figure 2.Two intense bands of Ni(NO 3)2centered at 1620cm −1and 1376cm −1were ascribed to asymmetric and symmetric vibra-tions of nitrate,respectively [25].After Ni(NO 3)2being impregnated on SiO 2,the position of the two bands of Ni(NO 3)2shifted to higher wavenumber about 1643cm −1and1385cm −1,respectively.Similar to our previous study [23],this shift to higher wavenumber might be contributed to the interaction between nickel nitrate and support SiO 2.3.2.2.Thermal Analysis.In order to study the formation of NiO from precursor,thermal analysis of 3NiSN before calcination was carried out (shown in Figure 3).The extra water should be removed by holding the precursor under O 2at 110∘C for 1h.The thermal oxidation degradation of the dried 3NiSN consisted of two main steps.The first weight loss (9.1wt%)at 110–240∘C region in TG together with a differential peak at around 224∘C in DTG curve was probably due to the dehydration of 3NiSN.The second large weight loss at region of 240–380∘C (11.1wt%)in TG,accompanied with a small endothermic peak around 293∘C in DTA,had been attributed to thermoxidative degradation of nickel nitrate.This decomposition step exhibited a differential peak around 277∘C in DTG profile.Above 380∘C,practically weight loss could not be observed any more.The TG-DTA curves confirmed the absolute volatility of water and nitrate and also the formation of NiO over catalysts around 380∘C.The calcination of 3NiSN beyond 380∘C would enhance the interaction between the NiO and SiO 2support,according to our earlier study [23].3.2.3.UV-Raman Analysis.Further evidence for the for-mation of NiO might be drawn from UV-Raman spectra exhibited in Figure 3.Herein,the spectrum for NiO was included as a reference.As seen from Figure 4,the intense and sharp peak at 1139cm −1,together with three weak peaks at 900,732,and 578cm −1,was assigned to the Raman responses of NiO.Similar to NiO reference,the peaks of 3NiSN center at about 1135,900,726,and 580cm −1were also attributed to NiO.Furthermore,compared with the reference of NiO,the four Raman peaks of NiO over 3NiSC appeared more intensive,thus suggesting that the NiO particles over 3NiSN catalyst were larger [23,26,27].3.2.4.XRD Analysis.XRD measurements were carried out to understand the crystalline structure of 3NiSN catalysts,and the results were presented in Figure5.The XRD patterns of all samples exhibited a broad and large peak around 22∘,which was attributed to amorphous silica of support.After calcination,the sample showed only the fcc-NiO phase,with typical reflections of the (111),(200),and (220)planes at 2θ=37∘,43∘,63∘,respectively.After being reduced with H 2for 4h,the peaks assigned to NiO disappeared,and three other peaks around 44∘,52∘,and 76∘for Ni (111),Ni (200),and Ni (220)planes were detected,thus inferring the successful transformation of NiO to metallic Ni after reduction with H 2.3.2.5.TEM Analysis.Further insight on the aggregation of Ni particles over the 3NiSN could be obtained by TEM analysis.Figures 6(a)and 6(b)exhibited the TEM images of 3NiSN after reduction and deactivation,respectively.The Ni particles over both catalysts were approximately spherical in shape.Highly dispersed Ni particles were detected for the Ni/SiO 2just after reduction.However,obvious glomeration200300400500600700Temperature (∘C)T G +D T G(a)200300400500600700Temperature (D T A∘C)(b)Figure 3:(a)TG +DTG and (b)DTA thermogram of 3NiSN dried at 100∘C.Raman shift (cm −1)I n t e n s i t y (a .u .)Figure 4:UV-Raman spectra of 3NiSN (calcined at 700∘C for 4h)and NiO (as a reference).of Ni particles was observed for the 3NiSN catalyst after deactivation.In order to make a profound analysis,the corresponding particle size distributions obtained from TEM were summarized in Figures 6(c)and 6(d)for 3NiSN after reduction and deactivation,respectively.The particle size values of reduced 3NiSN were distributed in a range of 16.1–84.0nm with the average size around 37.5nm.As for 3NiSN after deactivation,the mean size increased to 50.4nm2θ(deg)Ni NiOI n t e n s i t y (a .u .)Figure 5:XRD patterns of 3NiSN before and after reduction in H 2for 4h.with distributed range of 36.0–73.6nm.An evident particle aggregation was formed over 3NiSN catalyst,which was in accordance with the XRD result.3.2.6.H 2-TPR Analysis.TPR is an efficient method to char-acterize the reducibility of supported nickel-based catalysts.(a)(b)Particle diameter (nm)0.250.200.150.100.050.00R e l a t i v e p a r t i c l e n u m b e r (%)(c)0.200.150.100.050.00R e l a t i v e p a r t i c l e n u m b e r (%)Particle diameter (nm)(d)Figure 6:TEM images of (a)reduced 3NiSN and (b)deactivated 3NiSN,and histogram of the particle size distribution obtained from sampling of nanoparticles from TEM data (c)for reduced 3NiSN and (d)for deactivated 3NiSN.TPR profiles of 3NiSN catalysts were depicted in Figure 7.Two reduction peaks were observed for the fresh 3NiSN cata-lyst (just calcined)at 430∘C and 450∘C.The low-temperature peak might be contributed to the reduction of NiO which is negligible weak interaction with SiO 2.The high-temperature peak was caused by the reduction of nickel oxide which interacted weakly with SiO 2.Furthermore,ttthe reduction-oxidation cycle (redox)performance of a catalyst would strongly influence the catalytic activity for an oxidation involved reaction [28].Therefore,the redox performances of 3NiSN catalysts were investigated,and the corresponding experiment results were depicted in Figure 7.After beingreduced in H 2flow at 700∘C for 1h,the 3NiSN catalysts were reoxidized in O 2at different temperatures and then tested with H 2-TPR.No clear reduction peak of NiO was detected for 3NiSN with reoxidized temperature below 300∘C.As reoxidization temperature increased from 400to 700∘C,the rereduction temperature increased from ∼290to ∼370∘C;however,it was always less than the temperature needed to reduce the NiO of fresh 3NiSN.Distinctly,the weak NiO-SiO 2interaction over 3NiSN catalyst disappeared with repeat-ing oxidation-reduction-oxidation process.Studies from the previous work show that the strong interaction between NiO and support could suppress efficiently the sintering of200300400500600Temperature (FED C B A∘C)H 2c o n s u m p t i o n (a .u .)Figure 7:The reduction-oxidation cycle (redox)performance of 3NiSN catalysts with different reoxidization temperature (A:300∘C;B:400∘C;C:500∘C;D:600∘C;E:700∘C;F:fresh,just calcined).metallic nickel [21–23].Therefore,the disappearance of NiO-SiO 2interaction would lead to the sintering of active nickel particles at high reaction temperature.3.2.7.Effect of the Particle Size of Ni.It is generally accepted that the crystalline size of metallic nickel plays an important role in the catalytic performance for nickel-catalyzed reac-tions:smaller metallic Ni size helps to provide more active sites to reach the much better catalytic activity.Our previous works had also demonstrated this view [21,22].In order to investigate the particle size dependence of the catalytic reaction,the 3NiSN catalysts after different time (1.5h,2.0h,and 2.5h)reaction on stream were taken out to be estimated by XRD and calculated with the Scherrer equation (shown in Figure 8).For all the 3NiSN (even after deactivation),only Ni and amorphous SiO 2phase detected by XRD.No NiO phase was found,which meant no significant change in Ni phase was observed for 3NiSN even after deactivation.Noteworthily,the diffraction intensity of nickel crystalline increased with reaction time,which indicated the crystalline size of nickel on 3NiSN increased with reaction time.The crystalline size of nickel on 3NiSN as a function of reaction time was shown in Figure 9.The crystalline size of nickel was ∼30.3nm,∼32.6nm,∼33.6nm,and ∼34.6nm,for 3NiSN after 0h,1.5h,2h,and 2.5h reaction on stream,respectively.The change trend of Ni size was in conformance with the catalytic activity of 3NiSN in process of bined with H 2-TPR results above,with the process of CRPOM proceeding,the NiO-SiO 2interaction over 3NiSN catalyst weakened down as it disappeared.At the same time,the crystalline size of nickel increased with the weakening of NiO-SiO 2interaction,finally leading to the sintering of active nickel particles over 3NiSNcatalyst.2θ(deg)NiI n t e n s i t y (a .u .)Figure 8:The effect of reaction time on the XRD patterns of3NiSN.Reaction time (h)353433323130C r y s t a l l i n e s i z e o f n i c k e l (n m )Figure 9:Crystalline size of nickel as a function of reaction time.By comprehensively analyzing the characterization results,important information could be concluded.On one hand,graphic carbon was not detected in the spent 3NiSN catalyst by XRD and TEM,suggesting that no carbon deposition was formed during the reaction.On the other hand,except for the characteristic XRD peak of metallic nickel,no other nickel species (such as NiO)was detected,indicating that the transformation of active metallic Ni was not the reason for deactivation of 3NiSN.Importantly,the weak interaction between Ni and support disappeared asthe reaction proceeding,resulting in sintering of active nickel particles.This was the reason that3NiSN catalyst showed a rapid deactivation in the CRPOM reaction.4.ConclusionsIn this work,Ni/SiO2catalysts were prepared with nickel nitrate precursor by IWI method and characterized by FT-IR,TG-DTA,UV-Raman,XRD,TEM,and H2-TPR.By being calcined around380∘C,water and nitrate were volatilized absolutely to form NiO,which could be reduced into metallic Ni after being treated with H2at700∘C.The active nickel particles(around37.5nm)of3NiSN catalyst were dispersed highly but weakly interacted with SiO2support.However, this weak interaction disappeared after repeating oxidation-reduction-oxidation in the fluidized bed reactor at700∘C. Therefore,3NiSN catalyst suffered from obvious sintering of the active nickel particle.In light of these,a rapid deactivation of3NiSN was shown in the process of combination of CO2 reforming and partial oxidation of methane(CRPOM)to produce syngas.Conflict of InterestsThe authors declare that there is no conflict of interests regarding the publication of this paper. 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第23卷第4期 高 校 化 学 工 程 学 报 No.4 Vol.23 2009 年 8 月 Journal of Chemical Engineering of Chinese Universities Aug. 2009
文章编号：1003-9015(2009)04-0617-06
Pt-[HSO3-bvim]HSO4/SiO2双功能催化剂制备及其催化性能研究
崔咏梅, 王淑芳, 赵新强, 王延吉 (河北工业大学 化工学院, 天津 300130)
摘 要：针对离子液体固载中存在的使用物理方法固载的离子液体易流失的问题，采用化学键合的方法将离子液体固载于硅胶表面。合成了一种新型Brønsted酸性离子液体1-乙烯基-3-磺丁基咪唑硫酸氢盐([HSO3-bvim]HSO4)，并通过
自由基链转移反应将该酸性离子液体用化学键固定于氢硫基官能团化的硅胶表面，制备出了[HSO3-bvim]HSO4/SiO2固
体酸催化剂，再利用化学还原方法在该固体酸催化剂上负载金属铂，得到Pt-[HSO3-bvim]HSO4/SiO2双功能催化剂。采
用傅立叶红外光谱、核磁共振光谱、热重、元素分析和X射线衍射等方法对所制备的样品进行了结构表征。将该双功能催化剂应用于硝基苯催化加氢合成对氨基苯酚反应中，结果表明，其具有一定的催化活性。在85 ℃、4 h、0.4 MPa条件下，双功能催化剂可以多次重复使用，对氨基苯酚的收率大于3.1%。 关键词：铂-离子液体；双功能催化剂；结构表征；硝基苯；对氨基苯酚 中图分类号：O643.36；TQ426.6 文献标识码：A
Preparation and Catalytic Performance of Bi-Functional Catalyst Pt-[HSO3-bvim]HSO4/SiO2
CUI Yong-mei, WANG Shu-fang, ZHAO Xin-qiang, WANG Yan-ji (School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China)
Abstract: In order to solve the problem of ionic liquid leaking from its support, a chemical method was used to immobilize the ionic liquid on silica gel via covalent bond. A novel Brønsted type acidic ionic liquid 1-vinyl-3-sulfobutyl imidazolium hydrogen sulfate, [HSO3-bvim]HSO4, was synthesized. Then via free radical
chain transfer reaction, the [HSO3-bvim]HSO4 prepared was immobilized on silica gel functionalized by
sulphydryl to obtain [HSO3-bvim]HSO4/SiO2 solid acid catalyst. Finally, the metallic Pt was loaded on the
prepared solid acid catalyst by the chemical reduction method to obtain the bi-function catalyst Pt-[HSO3-bvim]HSO4/SiO2. The samples of prepared bi-function catalyst were characterized by FT-IR, NMR,
TG, elemental analysis and XRD, respectively. The hydrogenation of nitrobenzene to p-aminophenol (PAP) was used to evaluate the bi-function catalyst, and the results show that the PAP yield is higher than 3.1% under following conditions: hydrogenation temperature of 85℃, reaction time of 4 h and H2 pressure of 0.4 MPa. And
the bi-function catalyst can be reused for several times. Key words: Pt-ionic liquid; bi-functional catalysts; characterization; nitrobenzene; p-aminophenol
1 前 言 将均相前体固定在固体载体上是开发和制备非均相催化剂的一条重要路线，固载型催化剂具有易分离、回收和循环使用的优势[1]。
室温离子液体具有不挥发、高热稳定性、可设计性等特点，在催化、有机合成及萃取分离等领域应用广泛[2~4]。功能化Brønsted酸性离子液体是一类“可设计”的材料，因为其兼有固体酸无挥发和低腐蚀
收稿日期：2008-09-07；修订日期：2008-12-29。 基金项目：国家自然科学基金(20476022，20636030，20706011)；天津市自然科学基金(07JCZDJC00100)；河北省教育厅资助项目(2005005D)。 作者简介：崔咏梅(1969-)，女，河北石家庄人，河北工业大学博士生。通讯联系人：王延吉，E-mail：yjwang@hebut.edu.cn 618 高 校 化 学 工 程 学 报 2009年8月 图式1 [HSO3-bvim]HSO4离子液体的合成路线 Scheme 1 Synthesis route of [HSO3-bvim]HSO4 ionic liquid
H2SO4
O
NNS
O
O
+NN++
NN.3SO−4
HSO−SO3H
及液体酸流动性好、酸性位密度高和酸强度分布均匀等优点，已经在环境友好的酸催化方面表现出很大的潜力[5]。但是目前在用化学键将Brønsted酸性离子液体固定于固体载体上的研究极少，Qiao等[6]通过自
由基链转移反应首次将含有[CF3SO3]
−的酸性离子液体固定于氢硫基官能团化的硅胶表面，该体系可作为
酯化及硝基化反应的有效固相催化剂，催化剂的稳定性增强，产物的分离更容易，然而无论是酯化还是硝基化反应，都是相对简单的反应体系。 对氨基苯酚(PAP)是一种重要的化工原料及有机中间体，在医药和染料等行业中具有广泛的应用。尤其在医药工业中其需求量较大，主要用于扑热息痛和安诺明等药物的生产。硝基苯催化加氢法合成PAP，因其生产工序少，产品收率高，工艺条件也不十分苛刻，成为目前广泛采用的一种合成工艺，一般采用担载型金属铂作为加氢催化剂，如Pt/AC、Pt/SiO2及Pt/Al2O3等[7]。但该反应在硫酸溶液中进行，存在设
备腐蚀和酸液后处理等问题。为此，人们对固体酸负载Pt双功能催化剂上硝基苯加氢合成PAP反应进行了研究，试图用固体酸替代硫酸。武森涛等[8]以HF-SiO2、H-ZSM5及担载型杂多酸为载体制备了铂-
固体酸双功能催化剂，该催化剂在一定程度上降低了反应对硫酸浓度的要求，但在非酸性介质中催化剂的活性非常低。Chaudhari等[9]提出采用固体酸催化剂与Pt-S/C同时使用，将硝基苯与水混合后催化氢化，
也得到了PAP。所用的固体酸催化剂为离子交换树脂(Indion 130)，用量为3%~7%。硝基苯与水的物质量比为1:(5~7)，反应温度为50~100℃，反应压力为2.0 ~2.5 MPa，反应3 ~7 h，硝基苯转化率达97%，PAP收率为13.9％。Takayuki等[10]对金属-沸石型双功能催化剂上硝基苯气相加氢合成对氨基苯酚进行了研
究，发现Pt/HZSM-5具有最好的加氢和重排反应活性，在250℃条件下PAP收率最高为20%。马原辉[11]
制备了Pt-S2O82−/ZrO2催化剂，以水为反应介质，于反应温度150℃，氢气压力0.4 MPa条件下，Pt负载量为0.1%时，对氨基苯酚的收率为14.6%。可见，采用双功能固体酸催化剂虽然不使用硫酸，但目前仍存在反应条件苛刻、PAP收率较低及易失活等问题，并且，现有的研究表明，还未有人对双功能固体酸催化剂的重复使用进行探索。 本文设计合成了一种新型Brønsted酸性离子液体1-乙烯基-3-磺丁基咪唑硫酸氢盐([HSO3-bvim]HSO4，简称IL)，并通过自由基链转移反应首次将该酸性离子液体用化学键固定于氢硫基官
能团化的硅胶表面，制备出了[HSO3-bvim]HSO4/SiO2固体酸催化剂，再利用化学还原方法在该固体酸催
化剂上负载金属铂，得到Pt-[HSO3-bvim]HSO4/SiO2双功能催化剂。并将该双功能催化剂应用于硝基苯催
化加氢合成对氨基苯酚的反应中。
2 实验部分 2.1 [HSO3-bvim]HSO4/SiO2固体酸催化剂的制备
2.1.1 酸性离子液体[HSO3-bvim]HSO4合成
合成离子液体[HSO3-bvim]HSO4的反应式见图式1。将等摩尔的1-乙烯基咪唑和1,4-丁烷磺内酯在冰
浴中混合后于室温下搅拌72 h，得到白色两性离子固体，用无水乙醚洗涤、离心分离后真空干燥至恒重。将等摩尔的浓硫酸滴加到干燥后的两性离子中，在室温下反应4 h，用甲苯、乙醚洗涤后于40 ℃下真空干燥至恒重，得到[HSO3-bvim]HSO4离子液体，为褐色粘稠状液体。
2.1.2 3-巯丙基三甲氧基硅烷(MPS)改性硅胶(SiO2)制备
将10 g天津化工研究院生产的HV-01型SiO2加入到200 mL(2 mol⋅L
−1)的盐酸溶液中回流2 h，过滤