Tailoring Vibrational Excitation Pathways for High-Yield Oxidation of Methane to Methanol

The direct conversion of methane to methanol under mild conditions is a pathway to utilize methane and form a value-added fuel over distributed scales. However, overoxidation of methanol limits the maximum methanol yield, energy efficiency, and scalability of the process. For the first time, we show how molecular excitations and reaction time scales can be tailored in thermal nonequilibrium to break this limit. We engineer reaction pathways to form preferential intermediates that restrict the formation of unwanted byproducts. We synchronize vibrational excitations with active product removal in a one-pot reactor to control the accumulation of methanol and extend high methanol selectivity (>30%) to high methane conversion (>50%). We use these methods to demonstrate the highest methanol yield (21.4%) reported via single-step methane conversion at near-atmospheric conditions. We generalize these advances using process descriptors to demonstrate a pathway to even higher yields for energy-efficient methanol synthesis.