Clusters, alloys, and poisoning

This book deals with four major areas of selectivity stereoselectivity clusters, alloys, and poisoning shape selectivity and reaction pathway control. An overview of the book and reviews of each of the four major areas are included as introductory chapters. Each review is followed by individual contributions by attendees of the symposium. 

This review encompasses the general area of selectivity in catalysis as well as the four major specific areas discussed in this book Stereoselectivity Clusters, Alloys and Poisoning Shape Selectivity and Reaction Pathway Control. Examples are taken from the literature for each of these four areas of recent articles that focus on selectivity in catalytic reactions. Specific reviews of the four areas listed above can be found in the overview chapters by D. Forster and coworkers, K. J. Klabunde, M. E. Davis and coworkers and H. C. Foley and M. Klein. 

This review is an overview of recent literature research articles that deal with selectivity in catalysis. Four specific areas including stereoselectivity clusters, alloys and poisoning shape selectivity and reaction pathway control will be discussed. This review is not meant to be a complete discussion of these areas. It represents a small fraction of the research presently underway and a very minor fraction of the available literature in this subject. The order of topics will follow the four major areas oudined above, however, there is no particular order for the articles discussed in each section. 

There are several features of the different systems described above for the cluster, alloy and poisoning section that are common. First of all, the structural... 

The above literature review gives a comparison of different ways to control selectivity for both homogeneous and heterogeneous catalytic reactions. There are several common features for the four areas of stereoselectivity metal clusters, alloys and poisoning shape selectivity and reaction pathway control. In fact, many times more than one of these areas may be involved in a catalytic system. Some common features for all of these areas include precise control of the structural and compositional properties of the catalysts. This paper serves as an overview for the other manuscripts in this book. Specific review chapters on each of the four areas can be found in reviews that follow by D. Forster et al., K. J. Klabunde et al., M. E. Davis et al., and H. C. Foley and M. Klein et al. 

Clusters, alloys and poisoning. An overview Molecular organometallic chemistry on surfaces reactivity of metal carbonyls on metal oxides Mechanisms of skeletal rearrangements of hydrocarbons on metals elementary steps Surface-bound metal hydrocarbyls. Organometallic connections between heterogeneous and homogeneous catalysis... 

Rh, Pt, etc. Plans are under way in this laboratory for studies of the static and dynamic structure of CO on binary and ternary alloys (e.g., ruthenium/platinum/tin) in methanol for fuel-cell applications. Such alloys display enhanced resistance to CO poisoning, and the nature of this resistance is appropriate for NMR investigation. For example, Pt-CO bonding information such as Pt-C connectivities, CO orientation and clustering, are accessible by Ti, T2, isotope dilution, and related techniques. In fact, essentially all of the techniques used in the past 20 years to study the solid-gas interface should now be applicable to NMR-electrochemistry, with the added bonus of potential control. 

Thus, considering the results obtained by TPR and the high interaction existing between Ni and Co in the non-stoichiometric spinel matrix, the formation would be expected, to a certain extent, of a Ni-Co alloy in the Ni-Co-Zn-Al system after reduction in H2 at 500°C. This type of compound would lead to an important reduction in the number of three nickel atom arrangements on the cluster surface, responsible for the production of ethane. The consequence of this, once the hydrogenol)4 ic sites generated by addition of Co are poisoned, would be the suppression of the reaction pathway shown in Scheme 1. Therefore, ethylene... 

---