Oxidative Propane Dehydrogenation (ODHP) has emerged as an efficient alternative to direct Propane Dehydrogenation (PDH) for propylene production by coupling PDH with selective hydrogen combustion (SHC) using oxidants such as O2 and CO2 and overcoming the equilibrium limitations. Yet, controlling the unwanted side reactions remains a challenge. Tandem catalysts that integrate metals and metal oxides offer great promise in advancing such complex alkane chemistries. One recent example is tandem In2O3-Pt/Al2O3 catalyst, which has demonstrated improved performance by maintaining stable propylene selectivity over a longer duration. This catalyst, composed of Pt/Al2O3 catalyst overcoated with In2O3, effectively couples ODHP reactions while balancing activity and selectivity. However, there is a limited understanding of the metal-metal oxide interfaces and the role of the oxide overlayer at an atomic-level due to the vast configuration space arising from multiple phases and surface defects. To address this, a theoretical framework, combining the modified SurfGraph method with Density Functional Theory, is developed to systematically explore a phase space of ~104 configurations and identify stable Indium oxide (InOxHy) configurations on the platinum (Pt) surface. Exploring the stable structures uncovered a dynamic nature of InOxHy active sites on Pt that evolve with the thermodynamic conditions from synthesis to catalysis in ODHP. Thermodynamic and kinetic analyses indicate that InOxHy layer enhances propane activation while suppressing deep dehydrogenation by selectively blocking the Pt defect sites and curtailing side reactions. These insights are crucial for designing next-generation M₁@M₂Oₓ catalysts and advancing the understanding of metal oxide films deposited on metal via Atomic Layer Deposition (ALD).
