Fe/Fe3 C Boosts H2 O2 Utilization for Methane Conversion Overwhelming O2 Generation.

H2 O2 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 H2 O2 waste. Here, we fabricate heterogeneous Fenton-type Fe-based catalysts containing Fe-Nx sites and Fe/Fe3 C nanoparticles as a model to study this competition. Fe-Nx in the low spin state provides the active site for . OH generation. Fe/Fe3 C, in particular Fe3 C, promotes Fe-Nx sites for the homolytic cleavages of H2 O2 into . OH, but Fe/Fe3 C 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 H2 O2 in the chemical industry.