One-Step Synthesis of Air-Stable Sulfur-Doped Molybdenum Phosphide Catalyst

Transition-metal phosphides prepared from temperature-programmed reduction (TPR) are generally known to be unstable and prone to surface structure decomposition upon exposure to air. In this work, air-stable molybdenum phosphide (MoP) was prepared using TPR modified by sulfur. This catalyst was exposed to ambient atmosphere for up to 150 days and still maintained its surface and bulk structures as the fresh sample derived from in situ reduction. The metal phosphosulfide phase generated during TPR not only contributes to the solid structural properties but also exhibits superior catalytic activity in various hydrofining reactions compared to traditional MoP catalysts. Additionally, this preparation strategy was used to synthesize other sulfur-doped metal phosphides, such as CoP and Cu3P. Both of these catalysts exhibited excellent air-stability. Molybdenum phosphosulfide was derived from the conversion of a sulfur-containing precursor, and the reduction temperature required was lower than that of the conventional temperature-programmed reduction method. Both the oxygen resistance and reactivity of molybdenum phosphosulfide were superior to that of molybdenum phosphide. This excellent performance can be attributed to its unique structural characteristics.image