Production of propylene from ethanol over ZSM-5 co-modified with zirconium and phosphorus

Production of propylene from ethanol was studied over ZSM-5 co-modified with zirconium and phosphorus (P/Zr/ZSM-5). XRD and NH₃-TPD were used to characterize P/Zr/ZSM-5 together with H-ZSM-5 and the zirconium modified ZSM-5 (Zr/ZSM-5) for comparison. It was found that the concentration of strong acid sites on P/Zr/ZSM-5 was significantly reduced by the impregnation of phosphorus into Zr/ZSM-5. In the ethanol-to-propylene reaction, P/Zr/ZSM-5 exhibited a better catalytic performance than H-ZSM-5 and Zr/ZSM-5. The in situ UV-Vis spectrum of the ethanol adsorbed P/Zr/ZSM-5 revealed that the species of non desorbed aromatics were hardly produced and thus the formation of carbonaceous deposits was inhibited by the phosphorus modification.