A polybenzimidazole supported Mo(VI) complex (PBI.Mo) has been prepared and characterised. The catalytic activity of PBI.Mo for the epoxidation of cyclododecene and dodecene with tert-butyl hydroperoxide (TBHP) as an oxidant has been studied under different reaction conditions in a batch reactor. The stability of heterogeneous Mo(VI) catalyst was evaluated by recycling a sample in batch reaction using conditions that will form the basis of continuous process. The leaching of Mo species from PBI.Mo has been investigated by isolating any residue from reaction supernatant solutions following the removal of the heterogeneous catalyst, then using the residues as potential catalyst in epoxidation reactions. The batch epoxidation experimental data provided useful information for conducting continuous epoxidation in a reactive distillation column (RDC).