Facile Preparation of Ni 2 P with a Sulfur‐Containing Surface Layer by Low‐Temperature Reduction of Ni 2 P 2 S 6

Preparation of Ni 2 P by temperature‐programmed reduction (TPR) of a phosphate precursor is challenging because the P−O bond is strong. An alternative approach to synthesizing Ni 2 P, by reduction of nickel hexathiodiphosphate (Ni 2 P 2 S 6 ), is presented. Conversion of Ni 2 P 2 S 6 into Ni 2 P occurs at 200–220 °C, a temperature much lower than that required by the conventional TPR method (typically 500 °C). A sulfur‐containing layer with a thickness of about 4.7 nm, composed of tiny crystallites, was observed at the surface of the obtained Ni 2 P catalyst (Ni 2 P−S). This is a direct observation of the sulfur‐containing layer of Ni 2 P, or the so‐called nickel phosphosulfide phase. Both the hydrodesulfurization activity and the selective hydrogenation performance of Ni 2 P‐S were superior to that of the catalyst prepared by the TPR method, suggesting a positive role of sulfur on the surface of Ni 2 P‐S. These features render Ni 2 P‐S a legitimate alternative non‐precious metal catalyst for hydrogenation reactions.