(616e) Ab Initio Molecular Dynamics Spectra for Characterization of Hydrated Supported Metal Oxide Catalysts
AIChE Annual Meeting
2023
2023 AIChE Annual Meeting
Catalysis and Reaction Engineering Division
Catalyst Design, Synthesis, and Characterization IV: Experimental and Computational Catalyst Characterization
Thursday, November 9, 2023 - 9:12am to 9:30am
We compute Raman and power spectra for molybdenum oxide on γ-alumina via ab initio molecular dynamics (AIMD) and compare them to conventional 0 K density functional theory spectra. AIMD spectra can capture anharmonicities and features present at finite temperatures making them more amendable to comparison with experimental data. We find that the hydration conditions, often neglected for modeling simplicity, significantly affect spectral signatures. Additional analysis of the isolating hydroxyl group frequencies from power spectra suggests that the changes seen experimentally in infrared spectra can be related to surface reconstruction upon anchoring MoOx species on alumina. We also highlight system conditions that lead to different predicted frequencies between AIMD and traditional methods, which should be taken into consideration when directly comparing experimental and computational spectra.