Natural gas, consisting mainly of methane (CH₄), has a relatively low energy density at ambient conditions (~36 kJ l⁻¹). Partial oxidation of CH₄ to methanol (CH₃OH) lifts the energy density to ~17 MJ l⁻¹ and drives the production of numerous chemicals. In nature, this is achieved by methane monooxygenase with di-iron sites, which is extremely challenging to mimic in artificial systems due to the high dissociation energy of the C–H bond in CH₄ (439 kJ mol⁻¹) and facile over-oxidation of CH₃OH to CO and CO₂. Here we report the direct photo-oxidation of CH₄ over mono-iron hydroxyl sites immobilized within a metal–organic framework, PMOF-RuFe(OH). Under ambient and flow conditions in the presence of H₂O and O₂, CH₄ is converted to CH₃OH with 100% selectivity and a time yield of 8.81 ± 0.34 mmol g_cat⁻¹ h⁻¹ (versus 5.05 mmol g_cat⁻¹ h⁻¹ for methane monooxygenase). By using operando spectroscopic and modelling techniques, we find that confined mono-iron hydroxyl sites bind CH₄ by forming an [Fe–OH···CH₄] intermediate, thus lowering the barrier for C–H bond activation. The confinement of mono-iron hydroxyl sites in a porous matrix demonstrates a strategy for C–H bond activation in CH₄ to drive the direct photosynthesis of CH₃OH.

_{主要由甲烷（CH 4} ）组成的天然气在环境条件下具有相对较低的能量密度（~36 kJ l ^-1）。_{CH 4}部分氧化为甲醇 (CH ₃ OH) 将能量密度提升至~17 MJ l ^-1并推动大量化学品的生产。在自然界中，这是通过具有二铁位点的甲烷单加氧酶实现的，由于 CH ₄中 C-H 键的高解离能(439 kJ mol ^-1 ) 和易于过度使用，因此在人工系统中模拟该酶极具挑战性。 CH ₃ OH氧化成CO和CO ₂。_{在这里，我们报告了 CH 4}的直接光氧化在固定在金属-有机框架内的单铁羟基位点上，PMOF-RuFe(OH)。在 H ₂ O 和 O ₂存在的环境和流动条件下，CH ₄以 100% 的选择性转化为 CH ₃ OH，时间产率为 8.81 ± 0.34 mmol g _cat ^-1  h ^-1（相对于 5.05 mmol g _cat ^-1  h ^-1用于甲烷单加氧酶）。通过使用操作光谱和建模技术，我们发现受限的单铁羟基位点通过形成[Fe-OH···CH _{4结合CH 4}] 中间体，从而降低了 C-H 键活化的障碍。多孔基质中单铁羟基位点的限制证明了 CH _{4中 C-H 键活化以驱动 CH 3} OH的直接光合作用的策略。