The Key Role of Support Surface Hydrogenation in the CH₄ to CH₃OH Selective Oxidation by a ZrO₂‑Supported Single-Atom Catalyst

Direct conversion of methane to methanol has attracted much interest and yet remains a challenge. Here, we investigate the catalytic mechanisms for methane oxidation on the Rh single-atom catalyst (SAC) dispersed on zirconia support Rh₁/ZrO₂ by first-principles calculations. We find that, by comparison with other metal SACs dispersed on ZrO₂, the spontaneous dissociative adsorption of H₂O₂ on the Rh₁/ZrO₂ surface is a key factor that initiates the active site and hydrogenates the surrounding oxide support surface. We further reveal that the hydrogenation of the oxide support surface plays a key role in suppressing the further production of CH₃OOH and CO₂. Additionally, we propose a non-noble-metal Fe₁/ZrO₂ SAC as an active and selective catalyst for direct CH₄ to CH₃OH conversion, potentially performing better than the current best Rh₁/ZrO₂ SAC. Our findings provide insights for the design of highly selective and efficient catalysts for direct CH₄ to CH₃OH conversion.