Electrocatalytic methane oxidation to formate on magnesium based metal-organic frameworks

The electrochemical methane oxidation reaction is a potential approach for upgrading the nature-abundant methane (CH4) into value-added chemicals, while the activity and selectivity have remained substantially low due to the extremely inert chemical property of CH4. Inspired by the methane mono-oxygenase in nature, we demonstrated Mg-substituted metal-organic frameworks (Mg-MOF-74) containing a uniform distribution of Mg-oxo-Mg nodes as efficient catalytic sites. Compared to MgNi-MOF-74 and Mg(OH)2 without the Mg-oxo-Mg nodes, the Mg-MOF-74 presented a much enhanced CH4 electrooxidation performance, with a unique selectivity of producing formate. The maximum Faradaic efficiency of all liquid products reached 10.9% at 1.60 V versus reversible hydrogen electrode (RHE), corresponding to the peak production rate of 126.6 μmol·h-1·g-1.