Effects of P content in a P/HZSM-5 catalyst on the conversion of ethanol to hydrocarbons

A series of P/HZSM-5 catalysts prepared by impregnation method were used for ethanol conversion to lower olefins.The catalysts were characterized by X-ray diffraction(XRD),NH3-temperature-programmed desorption(NH3-TPD)and N2 adsorption-desorption measurements.It was found that the P/HZSM-5 catalysts showed high activity and selectivity toward light olefins.The selectivities of propylene and butylene can be improved with the introduction of phosphorus(P).When the content of P reached 3.0 wt%,more than 18.9% propylene in the gaseous products was obtained over the P/HZSM-5 catalyst at 450 ℃.The introduction of P modified the strong Br()nsted acid sites of the original HZSM-5 catalysts and P/HZSM-5 catalysts could resist coke formation and showed good stability.