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1、中南民族大学 硕士学位论文 铂、钯氧化物纳米颗粒的制备、表征与催化性能研究 姓名：王克明 申请学位级别：硕士 专业：物理化学 指导教师：黄涛;刘汉范 20070608 中南民族大学硕士学位论文 摘 要 摘 要 由于金属氧化物纳米材料所具有的优越性能它们在催化材料发光器件 光敏感材料等方面具有广阔的应用前景铂族金属纳米氧化物具有优良催化活性 及选择性但高分子稳定的水溶性纳米铂族金属纳米氧化物的制备及催化性能的 研究报道较少 本文探索了微波法在制备水溶性纳米 PtO2和纳米 PdO 方面的应用 考察了反应参数对纳米粒子制备的影响并对催化性能进行了初步研究 1. 以聚乙烯吡咯烷酮PVP为稳定剂利用微
2、波介电加热法使氯铂酸在碱 性条件下水解 制备得到了PVP稳定的水溶性纳米氧化铂胶体 利用UV- Vis TEM XPS 等对产物进行表征考察了反应因素的影响并对反应机理进行了初步探讨 微波辐照加热制备氧化铂纳米颗粒时反应时间短颗粒分布均匀粒径小分布 窄 稳定性好 且纳米颗粒粒径受溶液初始 pH 值影响小 在初始 pH 值为 5.71- 9.61 之间时水解反应的速率与 pH 关系不大而在强碱性下水解反应的速率明显加 快 2. 利用氯钯酸在碱性条件下的水解反应在微波辐照下制备得到 PVP 稳定的 纳米氧化钯胶体利用 TEMXRS 等对产物进行了表征考察了反应因素 的影响体系初始 pH 值在中性和
3、碱性范围内随着 pH 值的增大制得的氧化钯 纳米颗粒的粒径变化不大但在强酸条件下如 pH 值为 2.03 和 3.07 时制得纳 米颗粒粒径明显增大并且微波法制备氧化钯纳米颗粒时不同强酸弱碱盐的 存在对氧化钯粒径和分散性无影响 3. 将制备的氧化钯氧化铂胶体催化剂用于环己烯硝基苯和大豆油的催化 加氢反应初步考察了纳米氧化铂和氧化钯胶体的催化性能氧化铂胶体催化剂 的活性优于氧化钯胶体及市售氧化铂催化剂催化剂的重复使用中氧化铂胶体 的重复使用效果好催化剂失活率低而氧化钯胶体重复使用效果相对较差与 使用正己醇作溶剂对比使用甲醇作溶剂时胶体催化剂催化活性较好 关键词关键词微波聚乙烯吡咯烷酮氧化铂氧化钯
4、纳米颗粒胶体催化剂催 化活性 铂钯氧化物纳米颗粒的制备表征与催化性能研究 Abstract Owing to its excellent performance, metal oxides nanomaterials demonstrate potential application in the field of catalyst materials, LBD and light- sensitive material. In the field of catalyst, platinum group metal oxides have extraordinary catalytic per
5、formance and selectivity. However, much less is known concerning the study on the preparation and catalytic performance of the water- soluble platinum group metal oxide nannoparticles stabled by PVP. This article aims to study on the preparation of the water- soluble palladium oxide and platinum oxi
6、de nanoparticles with microwave irradiation heating, exploring the factors of the preparation of nanoparticles, and offers a preliminary study on the catalytic performance of them. 1. By hydrolytic decomposition of platinum chloride aqueous solution in alkalescence, water- soluble platinum oxide nan
7、oparticle colloids stabilized by PVP were prepared with microwave dielectric heating. The nanoparticles were characterized by UV- Vis, TEM and XPS. The influence factors of the reaction and the mechanism were investigated. The reaction time to prepare platinum oxide with microwave irradiation heatin
8、g was short, the platinum oxide nanoparticles obtained were well- dispersive and stable with a narrowly distributed particle size, and they were inconsiderably influenced by the initial pH value of the solution. The effect of initial pH on the hydrolytic velocity was little when the initial pH value
9、s were between 5.71 and 9.61, but the hydrolytic reaction accelerated obviously in strong alkalescence. 2. By hydrolytic decomposition of palladium chloride aqueous solution in alkalescence, water- soluble palladium oxide nanoparticle colloids stabilized by PVP were prepared with microwave dielectri
10、c heating. The nanoparticles were characterized by TEM, XRD and XPS. The influence factors of the reaction were investigated. When the system initial pH was in neutral and alkalescence condition, the particle sizes of palladium oxide nanoparticles changed little with the increase of the initial pH v
11、alue. However, when the system was in strong acid condition, such as the initial pH value of 2.03 and 3.07, the particle size increased obviously. The results indicated that different 中南民族大学硕士学位论文 weak acidic strong alkaline salts in the system had no effects on the particle size and dispersibility
12、of the palladium oxide nanoparticles. 3. The performed palladium oxide and platinum oxide colloid catalyst were put into use to different heterogeneous catalytic reaction systems, such as cyclohexene, nitrobenzene and soybean oil, tentatively to test its activity in the hydrogenation reaction. The c
13、atalytic performance of platinum oxide colloid catalyst was superior to palladium oxide colloid catalyst and market sold platinum oxide catalyst. The catalytic performance of platinum oxide colloid catalyst had good effect in repeated use, it deactivated itself considerably slowly, on the contrary,
14、palladium oxide colloid catalyst had bad effect in repeated use; compared with in the solvent of n- Hexanol, the catalytic performance of colloid catalysts were better in the solvent of methanol. Key Words Microwave; Polyvinylpyrrolidone; Palladium oxide; Platinum oxide; Nanoparticle; Colloid Cataly
15、st; Catalytic Hydrogenation 学位论文原创性声明学位论文原创性声明 本人郑重声明所呈交的论文是本人在导师的指导下独立进行研究所取 得的研究成果除了文中特别加以标注引用的内容外本论文不包含任何其 他个人或集体已经发表或撰写的成果作品 对本文的研究做出重要贡献的个 人和集体均已在文中以明确方式标明本人完全意识到本声明的法律后果 由本人承担 作者签名 日期 年 月 日 学位论文版权使用授权书学位论文版权使用授权书 本学位论文作者完全了解学校有关保留使用学位论文的规定同意学 校保留并向国家有关部门或机构送交论文的复印件和电子版 允许论文被查 阅和借阅 本人授权中南民族大学可以
16、将本学位论文的全部或部分内容编入 有关数据库进行检索可以采用影印缩印或扫描等复制手段保存和汇编本 学位论文 本学位论文属于 1保密在_年解密后适用本授权书 2不保密 请在以上相应方框内打 作者签名 日期 年 月 日 导师签名 日期 年 月 日 中南民族大学硕士学位论文 1 第一章 绪 论 1.1 引 言 纳米是物质尺寸的物理衡量单位其大小为 1 nm (纳米)10- 9 m (米)当物质 到纳米尺度以后大约是在 1100 nm 这个范围空间物质的性能就会发生突变 出现特殊性能呈现出不同于宏观物体也不同于孤立原子的特殊现象 纳米材料是组成相或晶粒在任一维度上尺寸介于 1100 nm 之间并且具有特 殊性能的材料也叫做超分子材料它是由粒径尺寸介于 1100 nm 之间的超细 颗粒组成的固体材料1纳米材料中包含若
