Selectivity of metals and alloys in hydrocarbon reactions

Abstract

A classification of selectivity phenomena and factors determining the selectivities is presented in brief. The alloying effects, as established, are also briefly reviewed. It is shown that with neohexane it is possible to test the selectivity for various reactions as well as the preference of metals and alloys for the formation of particular chemisorption complexes.

The metals Pt, Pd, Ir and Ni as well as the alloys Ni–Cu, Pt–Au and Pt–Ag have been tested by neohexane reactions with hydrogen.

It is shown in this paper that alloying with a Group Ib metal causes in most cases a shift from hydrogenolysis to isomerisation and, whereas αβ complexes are preferred by a pure metal, an αγ complex formation is relatively promoted by alloying. Carbon seems to have a similar effect.