Preparation, Characterization and Catalytic Behavior of Alumina-Supported Platinym/Tin Reforming Catalysts and Related Model Systems

这是对氧化铝负载的铂锡双金属烃类重整催化剂的基础研究。研究了模型和真实的催化表面，包括铂化的氧化锡薄膜、锡修饰的铂晶体、铂/锡合金表面，以及沉积在平面氧化铝、平面碳或多孔氧化铝上的铂和/或锡。使用了各种表面分析技术，包括X射线光电子能谱(XPS)、俄歇电子能谱(AES)、离子散射谱(ISS)、电子能量损失谱(EELS)、二次离子质谱仪(SIMS)、电子刺激解吸(ESD)、和紫外光电子能谱(UPS)。使用连接到超高真空表征系统的反应器在低压和高压下进行催化重整反应。表征研究表明，催化剂的性能与催化剂的结构元素有关。双金属重整催化剂，包括本项目研究的铂/锡体系，是能够从质量等级不断下降的原油中生产更多高辛烷值燃料的主要技术。它们在改善环境方面也发挥着越来越大的作用。尽管它们具有巨大的经济重要性，但人们对它们的了解仍然很少。这些催化剂产生的产量和附加值如此之大，即使是很小的改进也可能产生极大的经济效益。//

This is a fundamental study of alumina-supported, platinum-tin bimetallic, hydrocarbon reforming catalysts. Model and real catalytic surfaces are studied, including platinized tin oxide films, tin-decorated platinum crystals, platinum/tin alloy surfaces, and platinum and/or tin deposited on planar alumina, planar carbon, or porous alumina. Various surface analytical techniques are used, including X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), ion scattering spectroscopy (ISS), electron energy loss spectroscopy (EELS), secondary-ion mass spectrometry (SIMS), electron-stimulated desorption (ESD), and ultraviolet photoelectron spectroscopy (UPS). Catalytic reforming reactions are run at both low and high pressures using a reactor attached to the ultrahigh-vacuum characterization system. Catalytic behavior is correlated with elements of catalyst structure as elucidated by the characterization studies. Bimetallic reforming catalysts, including the platinum/tin system studied in this project, are the principal technology enabling production of larger amounts of high-octane fuels from ever-decreasing quality grades of crude oil. They also have an increasing role in environmental amelioration. Despite their great economic importance, they are still poorly understood. The volumes and added value produced with these catalysts are such that even small improvements can have egret economic benefit. //