The oxidation of CO and hydrocarbons over noble metal catalysts

Historically, the interest in catalysis by alloys shows periods of growth and periods of stagnation. The first period of growing interest was in the thirties when alloys were used to disclose the role of the order-disorder phenomena (see, e.g., Refs. 1–3). In the fifties alloys were used intensively to establish the role of the electronic structure of solids in catalysis (see, e.g., Refs 3–5). It was a period of very fast development in catalysis, the penetration of theoretical and experimental physics into catalysis initiated by the authors of The Electronic Theory of Catalysis (Dowden [5], Rienacker [2], Schwab [6], Eley [TI, Wolkenstein [a], Hauffe [9], and others), it brought much news and the experimental material on catalysis increased substantially. However, as far as the research on alloys itself is concerned, its success was debatable. The President of the IVth Congress on Catalysis in 1968, when closing the congress said about this period: “These systems (i.e. alloys) have been a danger...

Selectivity in catalysis by alloys

Publisher Summary This chapter discusses the compensation effect in heterogeneous catalysis that expresses the existence of interrelated kinetic behavior within a group of rate processes. The chapter focuses on the interrelation between kinetic characteristics and the chemistry of the participating surface rate processes. The chapter discusses the theoretical models and statistical methods used in the recognition of compensation phenomena. The chapter illustrates reported examples of compensation behavior and describes new instances of the effect that became apparent while making the present search of published kinetic data. A semiquantitative statistical analysis of these trends has been undertaken to provide a common basis for comparisons and to attempt to define criteria that enable meaningful relationships to be recognized. The compensation effect remains largely an empirical method of classifying kinetic observations and this has not been developed into a theoretical representation capable of predicting activities and patterns of reactivity in hitherto untested catalytic processes. Development of the usefulness of the correlation necessarily requires reexamination of many of the basic tenets of heterogeneous kinetic behavior.

Compensation Effect in Heterogeneous Catalysis

Chemical state and reactivity of supported palladium: I. Characterization by XPS and uv-visible spectroscopy

The great differences between the catalytic activities of the Group VIII and the Group IB metals have attracted much attention, especially over the last 25 years, and explanations of these differences have been sought through studying the manner of activity variation in alloys formed between suitable pairs of metals. Selection of suitable alloy systems has presented difficulties. Most work has naturally been done on systems exhibiting a continuous range of solid solution, and hence Pt-Au and Pt-Ag alloys, both of which have miscibility gaps, have not been widely studied. Much work has been done on Ni-Cu alloys, but recent results have demonstrated the presence of phase separation in this system, and this has called into question the interpretation of the earlier work. The Pd-Ag and Pd-Au systems appear to have complete miscibility, and have consequently been much studied: it is to them that this review is directed.

The Structure and Catalytic Properties of Palladium-Silver and Palladium-Gold Alloys

Catalytic oxidation: I. The oxidation of ethylene over Pd and PdAu alloys

Katalytische ox. 1. mitt. ox. von aethylen ueber pd und pd-au-katalysatoren 2. mitt. edelmetalle auf sio2traegern fuer die ox. von aethylen und propylen

H. R. Gerberich

Papers

Catalytic oxidation: I. The oxidation of ethylene over Pd and PdAu alloys

Katalytische ox. 1. mitt. ox. von aethylen ueber pd und pd-au-katalysatoren 2. mitt. edelmetalle auf sio2traegern fuer die ox. von aethylen und propylen