毫米级氧化铝多孔微球担载Keggin型多酸复合材料的制备及催化性能研究
发布时间：2019-05-18 04:52
【摘要】：多酸负载于高比表面积的介孔载体上做异相催化剂一直是多酸催化领域的研究热点。本论文用氨基修饰法将磷钨酸(简记为HPW)负载到毫米级的介孔γ-氧化铝微球表面制备了HPW-NH2-Al2O3和HPW-NH2-C8-Al2O3,用水热合成法将HPW、硅钨酸(简记为HSiW)负载到毫米级的介孔γ-氧化铝微球表面制备了HPW@HKUST-1@Al2O3和HSiW@HKUST-1@Al2O3。通过IR、XRD、XRF、ICP、SEM、NH3-TPD和TG-DTA等测试手段对这些负载型催化剂进行表征,结果表明杂多酸成功负载到了γ-Al2O3载体上,且催化剂保持了介孔结构。另外,对以上催化剂的催化性能分别进行了研究。研究结果主要有以下几个方面：(1)利用两种硅烷偶联剂—正辛基三甲氧基硅烷和3-氨丙基三乙氧基硅烷修饰介孔γ-氧化铝微球,再将HPW负载到γ-Al2O3微球中,制备了多酸负载型催化剂HPW-NH2-C8-Al2O3和HPW-NH2-Al2O3。 HPW-NH2-C8-Al2O3和HPW-NH2-Al2O3两种催化剂的酸催化活性用乙酸乙酯的水解反应来考察,实验结果表明0.2 g催化剂在65℃条件下的催化乙酸乙酯的水解效率分别为4.45%和8.27%,催化活性分别为245.4μmol·gacid-1·min-1和182.0μmol·gacid-1·min-1,采用UV-Vis测试两种催化剂在第一次使用时的溶脱率分别为2.17%和7.79%,而且两种催化剂在重复使用6次后催化效率分别降低了13.9%和62.9%。从实验结果可见,虽然催化剂HPW-NH2-Al2O3在第一次使用时催化效率和催化活性均高于HPW-NH2-C8-Al2O3,但是其重复使用效果远不如HPW-NH2-C8-Al2O3,该结果证明了正辛基基团在氧化铝表面形成的疏水空腔对磷钨酸具有保护作用。通过对比可以知道,HPW-NH2-C8-Al2O3催化剂是一种机械强度高、化学性质稳定、价格低廉、重复使用极其简便的优良催化剂。(2)通过氨基阳离子的静电引力作用,将HPW负载到氨基修饰的γ-Al2O3载体表面制备了多酸负载型催化剂HPW-NH2-Al2O3。将HPW-NH2-Al2O3应用于模拟油的萃取结合催化氧化脱硫实验中,结果表明60 mg的HPW-NH2-Al2O3可以在2h内将20 mL含硫量为350 ppmws的DBT正辛烷模拟油的含硫量降到2.8 ppmws,且催化剂易回收,重复使用5次后氧化脱硫效率由最初的99.2%仅降低到94.7%,表明这种HPW-NH2-Al2O3催化剂是一种优秀的除硫催化剂且可重复使用。(3)通过水热合成法在球型γ-Al2O3载体上负载了高分散的HKUST-1和多金属氧酸(简记为HPAs),制备了负载型多酸催化剂HPW@HKUST-1@Al2O3和HSiW@HKUST-1@Al2O3。将复合物作为酸催化剂用于乙酸乙酯和乙酸丁酯的酯化反应,实验结果表明,两种催化剂对酯化反应的催化选择性均为100%,其中对于合成乙酸乙酯的酯化反应,在酸醇比为2、反应温度为75℃的条件下用0.25 g催化剂反应2 h,HPW@HKUST-1@Al2O3催化剂的催化效率为92.3%HSiW@HKUST-1@Al2O3催化剂的催化效率为95.1%；而对于合成乙酸正丁酯的酯化反应,在酸醇比为2,反应温度为110℃的条件下用0.4g催化剂反应8h,HPW@HKUST-1@Al2O3催化剂的催化效率为82.7%,HSiW@HKUST-1@Al2O3催化剂的催化效率为84.9%。从实验结果可以看出,HSiW@HKUST-1@Al2O3催化剂的酸催化活性高于HPW@HKUST-1@Al2O3,且乙酸乙酯的酯合成效率高于乙酸丁酯。两种催化剂重复使用6次,催化效率均保持不变。HPW@HKUST-1@Al2O3和HSiW@HKUST-1@Al2O3两种催化剂的抗压强度较γ-Al2O3分别提高了60.0%和57.9%,表明球型γ-Al2O3起到载体的作用的同时还可以稳定HKUST-1和多酸的结构,防止其被破坏。
[Abstract]:The heterogeneous catalyst supported on the mesoporous support with high specific surface area has been a hot spot in the field of multi-acid catalysis. HPW-NH2-Al2O3 and HPW-NH2-C8-Al2O3 were prepared on the surface of mesoporous silica-alumina microspheres loaded with phosphotungstic acid (abbreviated as HPW) on the surface of millimeter-grade mesoporous silica-alumina microspheres by the amino-modification method, and the HPW was prepared by hydrothermal synthesis. The HPW@HKUST-1 @ Al2O3 and HSiW@HKUST-1 @ Al2O3 are prepared on the surface of the mesoporous silica-alumina microsphere loaded to the millimeter level by using silicotungstic acid (abbreviated as HSiW). The supported catalysts are characterized by IR, XRD, XRF, ICP, SEM, NH3-TPD and TG-DTA. The results show that the heteropoly acid is successfully loaded on the Al-Al2O3 carrier, and the catalyst keeps the mesoporous structure. In addition, the catalytic performance of the above catalysts was studied. The results of the study were as follows: (1) Using two silane coupling agents, n-octyltrimethoxysilane and 3-aminopropyltriethoxysilane to modify the mesoporous silica-alumina microspheres, the HPW-loaded catalyst HPW-NH2-C8-Al2O3 and HPW-NH2-Al2O3 were prepared. The catalytic activity of the two catalysts HPW-NH2-C8-Al2O3 and HPW-NH2-Al2O3 was investigated by the hydrolysis reaction of ethyl acetate. The experimental results showed that the hydrolysis efficiency of the catalyst was 4.45% and 8.27%, respectively, and the catalytic activity was 245.4. mu.mol 路 gacid-1 路 min-1 and 182.0. mu.mol 路 gacid-1 路 min-1, respectively. The dissolution rate of the two catalysts was 2.17% and 7.79%, respectively, and the catalytic efficiency of the two catalysts decreased by 13.9% and 62.9% after 6 times of re-use. It can be seen from the experimental results that, although the catalytic efficiency and catalytic activity of the catalyst HPW-NH2-Al2O3 are higher than that of the HPW-NH2-C8-Al2O3 at the time of the first use, the reuse effect of the catalyst is much lower than that of the HPW-NH2-C8-Al2O3, and the result shows that the hydrophobic cavity formed by the n-octyl group on the surface of the aluminum oxide has a protective effect on the phosphotungstic acid. By comparison, it is known that the HPW-NH2-C8-Al2O3 catalyst is an excellent catalyst with high mechanical strength, stable chemical property, low price and extremely simple and convenient re-use. (2) the HPW-NH2-Al2O3 is prepared by loading the HPW on the surface of the amino-modified Al-Al2O3 carrier by the electrostatic attraction of the amino cation. The application of HPW-NH2-Al2O3 in the extraction and catalytic oxidation of simulated oil shows that 60 mg of HPW-NH2-Al2O3 can reduce the sulfur content of 20 mL of DBT n-octane simulated oil with a sulfur content of 350 ppmws to 2.8 ppmws in 2 hours, and the catalyst is easy to recover. After 5 times of re-use, the oxidation desulfurization efficiency was only reduced to 94.7% from the original 99.2%, indicating that the HPW-NH2-Al2O3 catalyst is an excellent sulfur removal catalyst and can be used repeatedly. and (3) loading a highly dispersed HKUST-1 and a polyoxoacid (abbreviated as HPAs) on a spherical Al-Al2O3 carrier by a hydrothermal synthesis method, and preparing a supported catalyst HPW@HKUST-1 @ Al2O3 and HSiW@HKUST-1 @ Al2O3. The composite is used as an acid catalyst for esterification reaction of ethyl acetate and butyl acetate, The experimental results show that the catalytic selectivity of the two catalysts to the esterification reaction is 100%, in which, for the esterification reaction of the synthetic ethyl acetate, the reaction temperature of the two catalysts is 2, the reaction temperature is 75 DEG C, and the reaction is carried out with 0.25 g of the catalyst for 2 hours, The catalytic efficiency of the HPW@HKUST-1 @ Al2O3 catalyst is 92.3%, the catalytic efficiency of the Al2O3 catalyst is 95.1%, and for the esterification reaction for synthesizing n-butyl acetate, the catalytic efficiency of the HPW@HKUST-1 @ Al2O3 catalyst is 82.7% under the condition that the acid alcohol ratio is 2, the reaction temperature is 110 DEG C, the reaction temperature is 110 DEG C, and the catalytic efficiency of the HSiW@HKUST-1 @ Al2O3 catalyst is 82.7%, The catalytic efficiency of the HSiW@HKUST-1 @ Al2O3 catalyst is 84.9%. It can be seen from the experimental results that the catalytic activity of the HSiW@HKUST-1 @ Al2O3 catalyst is higher than that of the HPW@HKUST-1 @ Al2O3, and the ester synthesis efficiency of the ethyl acetate is higher than that of the butyl acetate. The two catalysts are used for 6 times, the catalytic efficiency is kept unchanged, and the compressive strength of the two catalysts of the .HPW@HKUST-1 @ Al2O3 and the HSiW@HKUST-1 @ Al2O3 is increased by 60.0% and 57.9%, respectively, and the structure of the HKUST-1 and the carbon dioxide can be stabilized at the same time, Preventing it from being damaged.
【学位授予单位】：北京化工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB33;O643.36
本文编号：2479689
[Abstract]:The heterogeneous catalyst supported on the mesoporous support with high specific surface area has been a hot spot in the field of multi-acid catalysis. HPW-NH2-Al2O3 and HPW-NH2-C8-Al2O3 were prepared on the surface of mesoporous silica-alumina microspheres loaded with phosphotungstic acid (abbreviated as HPW) on the surface of millimeter-grade mesoporous silica-alumina microspheres by the amino-modification method, and the HPW was prepared by hydrothermal synthesis. The HPW@HKUST-1 @ Al2O3 and HSiW@HKUST-1 @ Al2O3 are prepared on the surface of the mesoporous silica-alumina microsphere loaded to the millimeter level by using silicotungstic acid (abbreviated as HSiW). The supported catalysts are characterized by IR, XRD, XRF, ICP, SEM, NH3-TPD and TG-DTA. The results show that the heteropoly acid is successfully loaded on the Al-Al2O3 carrier, and the catalyst keeps the mesoporous structure. In addition, the catalytic performance of the above catalysts was studied. The results of the study were as follows: (1) Using two silane coupling agents, n-octyltrimethoxysilane and 3-aminopropyltriethoxysilane to modify the mesoporous silica-alumina microspheres, the HPW-loaded catalyst HPW-NH2-C8-Al2O3 and HPW-NH2-Al2O3 were prepared. The catalytic activity of the two catalysts HPW-NH2-C8-Al2O3 and HPW-NH2-Al2O3 was investigated by the hydrolysis reaction of ethyl acetate. The experimental results showed that the hydrolysis efficiency of the catalyst was 4.45% and 8.27%, respectively, and the catalytic activity was 245.4. mu.mol 路 gacid-1 路 min-1 and 182.0. mu.mol 路 gacid-1 路 min-1, respectively. The dissolution rate of the two catalysts was 2.17% and 7.79%, respectively, and the catalytic efficiency of the two catalysts decreased by 13.9% and 62.9% after 6 times of re-use. It can be seen from the experimental results that, although the catalytic efficiency and catalytic activity of the catalyst HPW-NH2-Al2O3 are higher than that of the HPW-NH2-C8-Al2O3 at the time of the first use, the reuse effect of the catalyst is much lower than that of the HPW-NH2-C8-Al2O3, and the result shows that the hydrophobic cavity formed by the n-octyl group on the surface of the aluminum oxide has a protective effect on the phosphotungstic acid. By comparison, it is known that the HPW-NH2-C8-Al2O3 catalyst is an excellent catalyst with high mechanical strength, stable chemical property, low price and extremely simple and convenient re-use. (2) the HPW-NH2-Al2O3 is prepared by loading the HPW on the surface of the amino-modified Al-Al2O3 carrier by the electrostatic attraction of the amino cation. The application of HPW-NH2-Al2O3 in the extraction and catalytic oxidation of simulated oil shows that 60 mg of HPW-NH2-Al2O3 can reduce the sulfur content of 20 mL of DBT n-octane simulated oil with a sulfur content of 350 ppmws to 2.8 ppmws in 2 hours, and the catalyst is easy to recover. After 5 times of re-use, the oxidation desulfurization efficiency was only reduced to 94.7% from the original 99.2%, indicating that the HPW-NH2-Al2O3 catalyst is an excellent sulfur removal catalyst and can be used repeatedly. and (3) loading a highly dispersed HKUST-1 and a polyoxoacid (abbreviated as HPAs) on a spherical Al-Al2O3 carrier by a hydrothermal synthesis method, and preparing a supported catalyst HPW@HKUST-1 @ Al2O3 and HSiW@HKUST-1 @ Al2O3. The composite is used as an acid catalyst for esterification reaction of ethyl acetate and butyl acetate, The experimental results show that the catalytic selectivity of the two catalysts to the esterification reaction is 100%, in which, for the esterification reaction of the synthetic ethyl acetate, the reaction temperature of the two catalysts is 2, the reaction temperature is 75 DEG C, and the reaction is carried out with 0.25 g of the catalyst for 2 hours, The catalytic efficiency of the HPW@HKUST-1 @ Al2O3 catalyst is 92.3%, the catalytic efficiency of the Al2O3 catalyst is 95.1%, and for the esterification reaction for synthesizing n-butyl acetate, the catalytic efficiency of the HPW@HKUST-1 @ Al2O3 catalyst is 82.7% under the condition that the acid alcohol ratio is 2, the reaction temperature is 110 DEG C, the reaction temperature is 110 DEG C, and the catalytic efficiency of the HSiW@HKUST-1 @ Al2O3 catalyst is 82.7%, The catalytic efficiency of the HSiW@HKUST-1 @ Al2O3 catalyst is 84.9%. It can be seen from the experimental results that the catalytic activity of the HSiW@HKUST-1 @ Al2O3 catalyst is higher than that of the HPW@HKUST-1 @ Al2O3, and the ester synthesis efficiency of the ethyl acetate is higher than that of the butyl acetate. The two catalysts are used for 6 times, the catalytic efficiency is kept unchanged, and the compressive strength of the two catalysts of the .HPW@HKUST-1 @ Al2O3 and the HSiW@HKUST-1 @ Al2O3 is increased by 60.0% and 57.9%, respectively, and the structure of the HKUST-1 and the carbon dioxide can be stabilized at the same time, Preventing it from being damaged.
【学位授予单位】：北京化工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB33;O643.36
【共引文献】
相关期刊论文 前10条
1 潘翠;魏荣卿;刘晓宁;季杰;姜岷;;聚苯乙烯星型磺酸型拟均相催化剂合成及其催化应用[J];功能材料;2013年09期
2 王亚军;陆科呈;冯长根;;多金属氧酸盐在染料废水光催化降解中的应用[J];安全与环境学报;2011年05期
3 朱雅婷;于颍;龚文朋;徐玉林;杨水金;;H_3PW_(12)O_(40)/SiO_2催化一锅法合成4-苯基-6-甲基-5-乙氧羰基-3,4-二氢嘧啶-2(H)-酮[J];宝鸡文理学院学报(自然科学版);2014年03期
4 Xi Xinguo;Zhang Jiling;Jiang Ruiyu;Xu Qi;;Application of Modified Attapulgite Clay as the Adsorbent in Gasoline Desulfurization[J];China Petroleum Processing & Petrochemical Technology;2014年03期
5 Liu Ni;Zhang Minghui;Wang Danhong;;Solvothermal Synthesis of V_2O_3 Catalysts for Oxidative Desulfurization of Dibenzothiophene[J];China Petroleum Processing & Petrochemical Technology;2014年03期
6 唐南方;赵小平;蒋宗轩;李灿;;分子氧为氧化剂磷钒酸盐为催化剂超深度氧化脱除柴油中的二苯并噻吩[J];催化学报;2014年09期
7 赵磊;田永胜;王光辉;邱江华;周勇;;CMC对HPMo/SiO_2结构及其催化模型油氧化脱硫性能的影响[J];材料导报;2014年24期
8 吕宝兰;叶明琰;徐玉林;杨水金;;H_3PW_(12)O_(40)/TiO_2-SiO_2催化合成3,4-二氢嘧啶-2(1H)-酮衍生物[J];辽东学院学报(自然科学版);2015年01期
9 谢东;何其慧;苏阳洋;王童薇;许仁富;胡柏星;;MCM-41分子筛负载亚硒核过氧钨酸盐催化剂催化二苯并噻吩氧化脱硫（英文）[J];催化学报;2015年08期
10 陈发旺;胡长文;;多金属氧簇催化研究进展[J];化学进展;2011年01期
相关博士学位论文 前7条
1 张铭;基于多酸材料的合成表征及其在燃油氧化脱硫中的应用[D];江苏大学;2013年
2 林志荣;脉冲电场对醇酸常温酯化反应影响研究[D];华南理工大学;2013年
3 李颖;真菌漆酶高效定向固定化新策略探索[D];山东大学;2014年
4 刘宏;碳一化学：甲烷二氧化碳重整制合成气及甲醇转化制烯烃研究[D];南京大学;2013年
5 李金涛;MSE型分子筛的制备及其在烷基化反应中的应用[D];南开大学;2014年
6 黄欢;吸附脱硫以及反应吸附脱硫吸附剂的制备、表征及性能研究[D];华东理工大学;2015年
7 胡小夫;金属有机框架组装杂多酸复合材料及其氧化脱硫性能[D];中国石油大学（华东）;2013年
相关硕士学位论文 前2条
1 杜强;掺杂稀土固体酸的制备及催化性能[D];四川师范大学;2013年
2 顾婷婷;杂多酸（盐）催化剂在酯化反应中的应用[D];聊城大学;2014年
，本文编号：2479689
本文链接：https://www.wllwen.com/kejilunwen/cailiaohuaxuelunwen/2479689.html
