The hydrogenation of akladienes. Part IV. The reaction of buta-1,3-diene with deuterium catalysed by rhodium, palladium, and platinum

Abstract

Reactions of buta-1,3-diene with deuterium have been investigated by use of alumina-supported rhodium (100 °C) palladium (17 °C), and platinum (20 °C) as catalysts. Reaction mechanisms are discussed in terms of the two general schemes presented in Part III. The three isomeric n-butenes are each formed by the processes C₄X₆(ads)+ X(ads)⇌ C₄X₇(ads) and C₄X₇(ads)+ X(ads)→ C₄X₈ where X = H or D. Butene isomerisation before desorption does not occur even though adsorbed butyl groups (intermediates in n-butane formation) were formed at the rhodium or platinum surfaces. In each reaction 50% or more of each butene is formed by the stepwise addition of two X-atoms, but sites also exist at which fast multiple exchange takes place. The sites at which butane is formed may be distinct from those at which butene formation occurs.