MoS₂ Catalysts Selectively Achieve High Yield of Liquid Oxygenate from Direct Conversion of Methane via Hydroxyl Radicals

Directly converting methane (CH₄) into liquid oxygenates (e.g., methanol) can circumvent the cost and engineering limits of natural gas transportation and storage. However, oxygenate yields from CH₄ remain low, and sulfur present in natural gas hinders activity in most catalysts. To overcome these barriers, we employ bulk molybdenum disulfide (MoS₂), a low-cost, robust catalyst which selectively produces large quantities of liquid oxygenates (>900 µmol/g_cat∙hr) from methane in the presence of hydroxyl (OH^•) radicals produced from dilute hydrogen peroxide (H₂O₂) at 75°C. Under realistic reaction conditions, MoS₂ partially and reversibly adopts a metastable, more electrically conductive phase (1T’) that can only be observed through in situ structural probes. Herein, we elucidate that redox synergy between H₂O₂ and MoS₂ produces active OH^• radical species that selectively transform CH₄ to surface methoxy species at the gas-solid liquid interface, leading to the unitary production of liquid oxygenate at a rate competitive with more costly precious metal catalysts, without additional catalyst preparation steps.