Effect of phosphorus modified USY on coupled hydrogenation and ring opening performance of NiW/USY + Al2O3 hydro-upgrading catalyst

Phosphorus modified USY (P-USY) prepared by incipient wetness impregnation method, was used as the acidic component of the hydro-upgrading catalyst support. XRD, BET, NH3-TPD, 31P and 27Al MAS NMR, H2-TPR, XPS and HRTEM were used to characterize the samples. The acidity and active metal sites WS2 of the catalyst were particularly investigated. Phosphorus modification led to the decrease of acidity and increase of WS2 average stacking layers of NiW/P-USY + Al2O3 catalysts compared with NiW/USY + Al2O3. The increased ring opening products yields of NiW/P-USY + Al2O3 catalysts can be achieved in the hydrogenation and ring opening of tetralin at 623 K. Especially, NiW/P-USY-2 + Al2O3 catalyst exhibited highest ring opening products yield of 31.4 wt.%. This advantage of phosphorus modification is believed due to the synergetic role of WS2 and the acidity.