Methanol Oxidation on RuO₂(110): Insights from DFT and Microkinetic Modeling

This study investigates methanol oxidation on RuO₂(110) using DFT combined with microkinetic modeling for TPRS simulations. Adsorbed methanol on RuO₂(110) was stabilized by three primary interactions: hydrogen from the OH group with a bridge oxygen atom, oxygen from the OH group with a Ru_cus atom, and the methyl group with a Ru_cus atom. Two methanol oxidation pathways were identified: the dehydrogenation pathway and the CH₂O₂ formation pathway. However, the TPRS simulations showed that the CH₂O₂ formation pathway predominates due to its kinetic and thermodynamic favorability. This study also predicted distinct oxidation behaviors based on CH₃OH coverage; complete oxidation to CO₂ is favored at low coverage, while CH₂O production is preferred at high coverage due to the relatively lower oxygen coverage. Our findings emphasize the critical role of surface oxygen in determining methanol oxidation efficiency on RuO₂(110), offering insights for designing better catalysts for direct methanol fuel cells.