Structure and reactivity of phosphorous modified H-ZSM-5 catalysts for ethanol dehydration

H3PO4/H-ZSM-5 catalysts were prepared by impregnation method with varying H3PO4 loadings from 5 to 20 wt%. The H3PO4 modified catalysts were found to be highly active and selective towards ethylene during ethanol dehydration at 673 K. However, the selectivity was found to strongly depend on the content of H3PO4, reaction temperature and WHSV. The catalysts were characterized using X-ray diffraction, NH3-TPD, N2 physisorption, 27Al, and 31P MAS NMR techniques.