Preparation of Highly Active Noble Metal Phosphide Catalysts

The effect of precursors on the active phase formation and hydrodesulfurization activities of noble metal phosphide catalysts was examined. The maximum activities of Pd-P and Rh-P catalysts prepared from acetylacetonato (acac) complex were observed at lower reduction temperatures than those for catalysts prepared from chlorides (Cl). The Pd-P catalyst prepared from acac also showed higher activity than that obtained from Cl. However, this trend was not observed in the Rh-P catalyst. The characterization results revealed that the higher activity of the Pd-P catalyst prepared from the acac is due to the highly dispersed Pd4.8P.