PEROVSKITE OXIDES - MATERIALS SCIENCE IN CATALYSIS
PEROVSKITE OXIDES - MATERIALS SCIENCE IN CATALYSIS
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DOI：
10.1126/science.195.4281.827
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发表时间：
1977-01-01
期刊：
影响因子：
56.9
通讯作者：
GALLAGHER, PK
中科院分区：
文献类型：
--
作者：
VOORHOEVE, RJH;JOHNSON, DW;GALLAGHER, PK
在对催化剂的需求日益增长的时代，钙钛矿已被重新发现为具有如此巨大多样性的催化剂家族，以至于广泛的科学学科已在其研究和应用中发挥作用。由于这种简单的结构可以容纳宽范围的离子和价态，钙钛矿适合于化学定制。合成钙钛矿相对简单，因为结构对不同化学的灵活性。许多陶瓷粉末制备技术适用于钙钛矿催化剂。在他们自己的权利，因此，他们的兴趣作为一个模型系统的相关性的固态参数和催化机制。最近发现氧化还原反应的速率和选择性与固体的热力学和电子学参数之间存在这种相关性。对于引言中提到的商业过程，钙钛矿催化剂尚未被证明是实用的。最初对这些催化剂的兴趣大多与它们在汽车尾气控制中的用途有关。目前在这一领域的兴趣集中在贵金属取代的钙钛矿抗硫中毒的单床，双床，和三效催化剂配置。迄今为止商业测试的配方显示出相当大的前景，但长期稳定性尚未得到证实。构成目前使用的商业催化剂的元素中有很大一部分可以掺入钙钛矿氧化物的结构中。相反，可以预期，适当配制的钙钛矿氧化物将显示出对各种化学转化的催化活性。尽管这一预期绝不是在现有催化剂体系的竞争面前取得商业成功的预测，但它使这些氧化物在催化化学转化研究中成为有吸引力的模型。通过适当的配方，可以定制许多理想的性能，包括过渡金属离子的价态，晶格中O的结合能和扩散，活性位点之间的距离，以及固体的磁性和导电性能。进一步的研究将极大地拓展钙钛矿催化剂的应用范围，加深对催化过程中固态参数的理解，并有助于实际催化过程的发展。
In a time of growing need for catalysts, perovskites have been rediscovered as a family of catalysts of such great diversity that a broad spectrum of scientific disciplines have been brought to bear in their study and application. Because of the wide range of ions and valences which this simple structure can accommodate, the perovskites lend themselves to chemical tailoring. It is relatively simple to synthesize perovskites because of the flexibility of the structure to diverse chemistry. Many of the techniques of ceramic powder preparation are applicable to perovskite catalysts. In their own right, they are therefore of interest as a model system for the correlation of solid-state parameters and catalytic mechanisms. Such correlations have recently been found between the rate and selectivity of oxidation-reduction reactions and the thermodynamic and electronic parameters of the solid.For commercial processes such as those mentioned in the introduction, perovskite catalysts have not yet proven to be practical. Much of the initial interest in these catalysts related to their use in automobile exhaust control. Current interest in this field centers on noble metal-substituted perovskites resistant to S poisoning for single-bed, dual-bed, and three-way catalyst configurations. The formulations commercially tested to date have shown considerable promise, but long-term stability has not yet been achieved.A very large fraction of the elements that make up presently used commercial catalysts can be incorporated in the structure of perovskite oxides. Conversely, it is anticipated that perovskite oxides, appropriately formulated, will show catalytic activity for a large variety of chemical conversions. Even though this expectation is by no means a prediction of commercial success in the face of competition by existing catalyst systems, it makes these oxides attractive models in the study of catalytic chemical conversion. By appropriate formulation many desirable properties can be tailored, including the valence state of transition metal ions, the binding energy and diffusion of O in the lattice, the distance between active sites, and the magnetic and conductive properties of the solid.Only a very small fraction of possible perovskite formulations have been explored as catalysts. It is expected that further investigation will greatly expand the scope of perovskite catalysis, extend the understanding of solid-state parameters in catalysis, and contribute to the development of practical catalytic processes.