Millesimal phosphorus promoted Pd/HY for efficient hydrogenation saturation

Deep hydrogenation saturation of polycyclic aromatic hydrocarbons is of great importance for oil upgrading and chemical production. Pd/HY is an active catalyst for hydrogenation, but its acid property and metal-support interaction should be further tailored for selective deep hydrogenation saturation. In this paper, trace phosphorus in the order of one thousandth were doped into Pd/HY using a facile wet impregnation method. The influences of phosphorus doping on the physicochemical properties and catalytic performance of Pd/HY were systematically studied. Surface acidity of HY support, dispersion and electric state of Pd nanoparticles, and metal-support interaction were finely tuned by changing the doping amount of phosphorus. On the catalyst doped with 0.09 wt% phosphorus, the side reaction of hydrocracking was suppressed and deep hydrogenation saturation of naphthalene was greatly promoted for achieving a high yield of decalin. Meanwhile, doping millesimal phosphorus greatly enhanced the stability of the catalyst due to efficient inhibition of aggregation and leaching of active Pd nanoparticles in the harsh reaction environment and severe recycling process.