Direct Transformation of Ethylene to Propylene by Cascade Catalytic Reactions under Very Mild Conditions

Converting ethylene to propylene (ETP) at low temperatures, without adding other hydrocarbons, is a great challenge today. In this study, we explored an ETP process based on cascade reactions, operated in a one-pot mode over two catalysts. Using a single-flow reactor, under identical conditions (T and P), ethylene has been partially transformed over Ni-AlKIT-6 into 2-butene, which then reacted with the unconverted ethylene over ReOx/Al2O3 to obtain propylene. The effects of Re loading (4-12%), reaction temperature (60-120 degrees C), and pressure (0.1-3 MPa) on the ETP process have been examined. The nature of the catalytic sites and their stability against deactivation have also been studied. Additionally, we explored for the first time the selective dimerization of the ethylene over Ni-AlKIT-6 at low temperatures.