Fe/Fe3C Boosts H2O2 Utilization for Methane Conversion Overwhelming O2 Generation

H2O2 as a well‐known efficient oxidant is widely used in the chemical industry mainly because of its homolytic cleavage into .OH (stronger oxidant), but this reaction always competes with O2 generation resulting in H2O2 waste. Here, we fabricate heterogeneous Fenton‐type Fe‐based catalysts containing Fe‐Nx sites and Fe/Fe3C nanoparticles as a model to study this competition. Fe‐Nx in the low spin state provides the active site for .OH generation. Fe/Fe3C, in particular Fe3C, promotes Fe‐Nx sites for the homolytic cleavages of H2O2 into .OH, but Fe/Fe3C nanoparticles (Fe0 as the main component) with more electrons are prone to the undesired O2 generation. With a catalyst benefiting from finely tuned active sites, 18 % conversion rate for the selective oxidation of methane was achieved with about 96 % selectivity for liquid oxygenates (formic acid selectivity over 90 %). Importantly, O2 generation was suppressed 68 %. This work provides guidance for the efficient utilization of H2O2 in the chemical industry. In a heterogeneous Fenton‐type FeNx/C catalyst, Fe‐Nx sites and graphene‐encapsulated Fe/Fe3C nanoparticles promote the efficient generation of hydroxyl radicals from H2O2 for the highly selective oxidation of methane to formic acid. The reaction mechanism at the active sites has been studied.