Fe/Fe 3 C Boosts H 2 O 2 Utilization for Methane Conversion Overwhelming O 2 Generation

H 2 O 2 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 O 2 generation resulting in H 2 O 2 waste. Here, we fabricate heterogeneous Fenton‐type Fe‐based catalysts containing Fe‐N x sites and Fe/Fe 3 C nanoparticles as a model to study this competition. Fe‐N x in the low spin state provides the active site for . OH generation. Fe/Fe 3 C, in particular Fe 3 C, promotes Fe‐N x sites for the homolytic cleavages of H 2 O 2 into . OH, but Fe/Fe 3 C nanoparticles (Fe 0 as the main component) with more electrons are prone to the undesired O 2 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, O 2 generation was suppressed 68 %. This work provides guidance for the efficient utilization of H 2 O 2 in the chemical industry.