Bioinspired microenvironment modulation of metal-organic framework-based catalysts for selective methane oxidation.

Inspiration from natural enzymes enabling creationary catalyst design is appealing yet remains extremely challenging for selective methane (CH ₄ ) oxidation. This study presents the construction of a biomimetic catalyst platform for CH ₄ oxidation, which is constructed by incorporating Fe-porphyrin into a robust metal-organic framework, UiO-66, furnished with saturated monocarboxylic fatty acid bearing different long alkyl chains. The catalysts demonstrate the high efficiency in the CH ₄ to methanol (CH ₃ OH) conversion at 50 °C. Moreover, the selectivity to CH ₃ OH can be effectively regulated and promoted through a fine-tuned microenvironment by hydrophobic modification around the Fe-porphyrin. The long-chain fatty acids anchored on the Zr-oxo cluster of UiO-66 can not only tune the electronic state of the Fe sites to improve CH ₄ adsorption, but also restrict the amount of H ₂ O ₂ around the Fe sites to reduce the overoxidation. This behavior resembles the microenvironment regulation in methane monooxygenase, resulting in high CH ₃ OH selectivity.
Competing Interests: Conflict of interest The authors declare that they have no conflict of interest.
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