First Annual Meeting - Chromosome Segregation and Aneuploidy Group on April 24-29, 1995 in Sorrento, Italy

本研究验证了一个假设，即在某些反应中，特别是在氢异构化反应中，由两个组成不同的颗粒表面组成的催化剂将优于具有单一活性表面的简单催化剂。设计范例需要少量的贵金属（钯、铂、铑或铱），它们可以解离氢，然后氢溢出到合金表面，对所需产品具有高选择性；这些合金由贱金属（铁或钴）和稀土（铈、镨或镧）组成。其他研究表明，碳载体可能有利于形成具有所需结构的表面；本工作研究的支撑材料包括高表面积和低表面积的碳、石墨、氧化铝和二氧化硅。初步研究表明，铁铈钯对丁烯的加氢异构反应具有高活性和高选择性。在这项工作中，丁二烯的部分加氢被用作附加的测试反应。利用x射线衍射、穆斯堡尔光谱、微量热法和透射电子显微镜对颗粒的表面和体结构进行了探测。在这项工作中确立的原则应适用于广泛的工业过程。正在研究的具体系统将允许立即应用于《清洁空气法》所要求的“重新配方”汽油的生产，并应消除与遵守有关的成本差异。＊＊＊

Abstract Jonathan Phillips This study tests the hypothesis that catalysts consisting of two compositionally distinct particle surfaces will be superior to simpler catalysts with a single active surface for certain reactions and specifically for hydroisomerization. The design paradigm calls for a small amount of a noble metal (palladium, platinum, rhodium, or iridium) that can dissociate hydrogen, which then spills over to an alloy surface with high selectivity for the desired product; these alloys consist of a base metal (iron or cobalt) and a rare earth (cerium, praseodynium, or lanthanum). Other studies suggest that carbon supports may favor formation of surfaces with the desired structures; supports studied in this work include both high surface-area and low-surface area carbon, graphite, alumina, and silica. Preliminary studies using iron-cerium-palladium on carbon show both high activity and high selectivity for hydroisomerization of 1-butene. In this work partial hydrogenation of butadiene is used as an additional test reaction. Surface and bulk structures of the particles are probed using X-ray diffraction, Mossbauer spectroscopy, microcalorimetry, and transmission electron microscopy. The principal being established in this work should apply to a wide range of industrial processes. The specific systems under study will permit immediate application to the production of "reformulated" gasoline required by the Clean Air Act and should eliminate the cost differential associated with compliance. ***