Metal-CeO₂ Interfaces and their Role in Methane Conversion to Fuels

Methane dry reforming (MDR), which converts CH₄ and CO₂ into syngas (CO/H₂), is gaining attention for its environmental benefits. Additionally, direct conversion of CH₄ to CH₃OH is a highly sought goal in catalysis. Metal-ceria systems, particularly those involving Ni, Co, and Pt on CeO₂(111), have emerged as promising catalysts for these processes. This presentation explores recent theoretical and experimental advances in understanding these catalysts, using DFT+U simulations alongside in situ/operando techniques (AP-XPS, XRD, XAFS) and catalytic testing [1,2,3,4].

A key finding is that low metal loading, combined with ceria’s ability to stabilize oxidized metal species by re-localizing electrons on f-states, is essential for CH₄ activation at room temperature and efficient CH₄ reforming at relatively low temperatures (700 K). Notably, the room-temperature activation of methane on low-loaded metal/CeO₂ deviates from traditional linear scaling relationships, highlighting how this nanomaterial overcomes the “tyranny of linear scaling” [5]. This presents a promising strategy for developing active and stable catalysts for methane activation and conversion.

Furthermore, we present evidence that low Ni loadings on CeO₂ can catalyse methanol production at low temperatures (450 K) with high selectivity, using oxygen and water [6]. Additionally, Pd-CeO₂ catalysts modified with carbon (Pd-iC-CeO₂) achieve 100% selectivity for methanol in the liquid phase at 350 K using hydrogen peroxide as the oxidant [7]. The role of solvent interactions in enhancing selectivity is also discussed, highlighting the potential of these catalysts to drive cost-effective and selective methane conversion to valuable products.