Advances in selective ethylene trimerisation – a critical overview

Linear alpha olefins such as 1-hexene are widely used in the chemical industry. Over the past 15 years there has been considerable industrial interest in the selective trimerisation of ethylene to 1-hexene, which seems to be the preferred on-purpose route to this product. This article aims to provide a historical overview of all developments in the field of selective olefin trimerisation. During the discussion of the individual catalyst systems, special attention is also paid to features such as catalyst activity, reaction selectivity and relative catalyst cost, all of which would play a role in selecting the best technology. Various mechanistic aspects of this novel chemical reaction are also discussed in detail. The article concludes with a discussion on the major findings of a number of recent theoretical studies on trimerisation catalysis.