sba15介孔分子筛的改性及其催化性能.docx

Classified Index:O61
.:
Dissertation for the Master’s Degree of Science
SYNTHESIS, MODIFICATION OF MESOPOROUS SIEVE SBA-15 AND THEIR CATALYSIS PROPERTIES
Candidate: Li Ying
Supervisor: Prof. Qiang Liang sheng
Academic Degree Applied for: Master of Science
Specialty: anic Chemistry
Affiliation: Department of Applied Chemistry
Date of Defence: July, 2007
Degree-Conferring-Institution: Harbin Institute of Technology
摘 要
介孔分子筛 SBA-15 具有较高比表面积、孔道结构规则及孔径易于调节、热稳定性和水热稳定性较好、表面易改性等优点,在催化化学和吸附分离等领域有很大的潜在应用前景。纯 SBA-15 介孔分子筛酸性弱,在其骨架中引入 Al、P、B 等非硅原子之后,可获得一定强度的酸性中心,从而具备酸催化的功能。本研究在制备纯 SBA-15 的基础上,对其进行了掺杂 Al 原子和负载 H3PO4 改性,并研究了 P-SBA-15 对丙烯酸与正丁醇酯化反应的催化作用。
在强酸性条件下,以三嵌段共聚物 P123 为模板剂,正硅酸乙酯为硅源, 水热合成 SBA-15 介孔分子筛。并通过 XRD、BET、FT-IR、TEM 等分析手段对样品进行了表征。结果表明:合成的样品具有长程有序的六方介孔结构,各反应物的物质的量比为:n(P123):n(HCl):n(H2O):n(TEOS)=::139:1,晶化时间为 3d。
以异丙醇铝为铝源,采用原位法和后嫁接法两种方法,合成了 Al/SBA-15 和 Al-SBA-15 介孔分子筛,比较了 Al/SBA-15 和 Al-SBA-15 介孔分子筛的合成机理,并通过 XRD、BET 分析手段对样品进行了表征。结果表明,掺铝后的 SBA-15 均保持了高度有序的六方孔道结构,两种方法合成的 Al/SBA-15 和 Al-SBA-15 介孔分子筛具有不同的孔径、孔容及比表面积。
采用浸渍法合成了 P-SBA-15 介孔分子筛催化剂,并用于催化丙烯酸与正丁醇的酯化反应,分别考察了反应温度、反应时间、酸醇物质的量比、催化剂的用量等因素对催化作用的影响。研究结果表明,P-SBA-15 介孔分子筛具有较高的催化活性。当丙烯酸与正丁醇物质的量比为 1:、催化剂用量为反应体系总质量的 5%、反应温度为 120℃、反应时间为 5h 时,丙稀酸丁酯的最高产率为 %。
关键词 介孔分子筛;改性;SBA-15;酯化反应催化
Abstract
The mesoporous molecular sieve SBA-15 has been received much attention in the fields of catalytic chemistry and adsorption-separation, due to the advantages of high surface area, ordered and tunable pore structure, high thermal and hydwthermal stability and facile modification of surface properties. In spite of the weak acidicity, SBA-15 can still be used as acidic catalyst when some non-silicon atoms, such as Al, P, B, were introduced into its skeleton and, thus, some acid centers were obtained. In this thesis, SBA-15 was firstly prepared, and then SBA-15 has modified by Al doping and H3PO4 loading, and the catalytic activity of P-SBA-15 on the esterification reaction of acrylate and n-butanol w