Compound Precursors to Mixed Metal Oxides

混合金属氧化物的化合物前体

• 批准号: 8915897
• 负责人: Kenneth Poeppelmeier
• 金额: $ 30.51万
• 依托单位: Northwestern University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-04-15 至 1994-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8915897&HistoricalAwards=false
• 关键词: Compound; Precursors; Mixed; Metal; Oxides

Reactions of one solid with another that occur at room temperature are not common in solid state chemistry. The reaction of metal hydroxides with salts is a particularly unusual example. This reaction they have called salt imbibition and it provides a new synthetic method for the preparation of high surface area (HSA) mixed metal oxides. Such compound precursors can be decomposed to give mixed oxides. Because all reactions can be carried out at low temperature, the products will not sinter and will retain their porous character and relatively high surface area. Compared to commercially available HSA oxides (e.g. aluminas, silicas and zeolites) mixed metal oxides offer an entirely new range of materials for applications in ceramics, catalysis and emerging materials science applications. Because HSA mixed oxides have not been widely available their surface chemistry is unknown. Ion-exchange, a diffusion dependent reaction, occurs not only near the surace but can be an important reaction in the interior of a mixed metal oxide crystallite. A related intrinsic characteristic of a HSA oxide is its solid-acid chemistry. To distinguish the type of surface chemistry that can be expected from these novel materials well known reactions such as the isomerization of 3,3-dimethylbutene to 2,3- dimethylbutenes, 2- and 3-methylpentenes, and n-hexenes will be investigated.

一种固体与另一种固体在室温下发生的反应在固态化学中并不常见。金属氢氧化物与盐的反应是一个特别不寻常的例子。这一反应被称为盐渗吸反应，为制备高表面积混合金属氧化物提供了一种新的合成方法。这种化合物前体可以分解成混合氧化物。因为所有的反应都可以在低温下进行，所以产物不会烧结，并保持其多孔性和相对较高的表面积。与市售的HSA氧化物（如氧化铝、二氧化硅和沸石）相比，混合金属氧化物为陶瓷、催化和新兴材料科学应用提供了全新的材料范围。由于HSA混合氧化物尚未广泛应用，其表面化学性质尚不清楚。离子交换是一种依赖于扩散的反应，不仅发生在表面附近，而且在混合金属氧化物晶体内部也是一个重要的反应。HSA氧化物的一个相关的内在特性是它的固酸化学性质。为了区分这些新材料的表面化学类型，我们将研究众所周知的反应，如3,3-二甲基丁烯异构化为2,3-二甲基丁烯、2-和3-甲基戊烯以及正己烯。