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

Abstract

The selective partial oxidation of methane to methanol using molecular oxygen represents a long-standing challenge in the field of catalysis, inspiring extensive study for many decades However, to date considerable challenges still prevent large-scale production via the aerobic route. Herein, we report a Pd-containing phosphomolybdate catalyst (Pd/CsPMA), which, after activation by H2 converts methane and O2 almost exclusively to methanol at room temperature. The highest activity reached 67.4 µmolgcat−1h− 1. Pd enables rapid H2 activation and H spillover to phosphomolybdate for Mo reduction, while facile O2 and subsequent methane activation occurs on the reduced phosphomolybdate sites. Phosphomolybdate maintained its Keggin-type structure during the reaction, and the catalyst is reused 4 times without losing activity. The work reveals the underexplored potential of Mo-based catalyst for aerobic methane oxidation and highlights the importance of regulating the chemical valance state to construct methane active sites.