High-Pressure Electro-Fenton Driving CH4 Conversion by O2 at Room Temperature

Electrochemical conversion of CH 4 to easily transportable and value-added liquid fuels is highly attractive for energy-efficient CH 4 utilization, but it is challenging due to the low reactivity and solubility of CH 4 in the electrolyte. Herein, we report a high-pressure electro-Fenton (HPEF) strategy to establish a hetero-homogeneous process for the electrocatalytic conversion of CH 4 by O 2 at room temperature. In combination with elevation of reactant pressure to accelerate reaction kinetics, it delivers an unprecedented HCOOH productivity of 11.5 mmol h –1 g Fe –1 with 220 times enhancement compared to that under ambient pressure. Remarkably, an HCOOH Faradic efficiency of 81.4% can be achieved with an ultralow cathodic overpotential of 0.38 V. The elevated pressure not only promotes the electrocatalytic reduction of O 2 to H 2 O 2 but also increases the reaction collision probability between CH 4 and •OH, which is in situ generated from the Fe 2+ -facilitated decomposition of H 2 O 2 .