H2-reduced phosphomolybdate promotes room-temperature aerobic oxidation of methane to methanol

The selective partial oxidation of methane to methanol using molecular oxygen (O-2) represents a long-standing challenge, inspiring extensive study for many decades. However, considerable challenges still prevent low-temperature methane activation via the aerobic route. Here we report a precipitated Pd-containing phosphomolybdate, which, after activation by molecular hydrogen (H2), converts methane and O-2 almost exclusively to methanol at room temperature. The highest activity reaches 67.4 mu mol gcat(-1) h(-1). Pd enables rapid H-2 activation and H spillover to phosphomolybdate for Mo reduction, while facile O-2 activation and subsequent methane activation occur on the reduced phosphomolybdate sites. Continuous production of methanol from methane was also achieved by concurrently introducing H-2, O-2 and methane into the system, where H-2 assists in maintaining a moderately reduced state of phosphomolybdate. This work reveals the underexplored potential of such a Mo-based catalyst for aerobic methane oxidation and highlights the importance of regulating the chemical valence state to construct methane active sites.

Automated summary

This study reports a new catalyst that efficiently converts methane and oxygen into methanol. By activating hydrogen and regulating the chemical valence state, high-efficiency catalytic oxidation of methane is achieved.