Lattice Oxygen‐Mediated Selective Oxidation of Dimethoxymethane: A Contrast with Methanol Oxidation Mechanism

Selective oxidation of dimethoxymethane (DMM) to formaldehyde offers an atomeconomical alternative to methanol (MeOH) oxidation. However, DMM oxidation is more complex than that of MeOH, and its mechanism remains unclear. Herein, we adopted the methodology established for MeOH oxidation to systematically compare DMM and MeOH oxidation over iron‐molybdenum catalysts via catalytic performance tests and multi‐characterization techniques, including temperature‐programmed desorption (TPD), x‐ray diffraction (XRD), and X‐ray photoelectron spectroscopy (XPS). Under aerobic conditions, DMM was completely converted, whereas MeOH reached 96.9% conversion, and both exhibited formaldehyde selectivity above 92%. Under anaerobic conditions, the average oxidation states (AOS) of Mo and Fe decreased to 5.33 and 2.36 for DMM, compared to 5.61 and 2.66 for MeOH, confirming deeper catalyst reduction and greater involvement of lattice oxygen in the DMM pathway. These findings demonstrate that DMM oxidation follows the Mars‐van Krevelen (MvK) mechanism. Resolving these key mechanistic uncertainties not only advances the fundamental understanding of DMM selective oxidation but also provides a rational basis for designing improved catalysts.