Over recent years, there has been interest in strategies to heterogenise homogenous catalysts in the quest for more selectivity in olefin epoxidation.

In their Dalton Perspective, Kavita Jain and Fritz Kühn look at immobilized molybdenum oxo and carbonyl complexes which are important catalysts for epoxidation.  These supported catalysts combine the properties of both homogenous catalysts, such as reactivity, control and selectivity with enhanced stability and recyclability, characteristic of heterogeneous catalysts.  A variety of ways exist in which to immobilise the molybdenum complexes, including the use of zeolites or mesoporous structures as support and the use of ionic liquids.

Zeolite supported catalyst

Future developments in the field look towards achieving improved recyclability of these catalysts, the authors say.