@article{Shah2023,
abstract = {Supported molybdenum oxides have been widely employed as catalysts for variety of reactions including upgrading of bio-oil via hydrodeoxygenation. Herein, we perform spin-polarized density functional theory calculations to investigate the structures and reactivity of monomeric MoO species supported on ZrO in the absence and presence of hydroxyl(s). Monomeric molybdenum moieties were found to have a mono-oxo (one molybdenyl), di-oxo (two molybdenyls) or a pero-oxo (one molybdenyl and Mo coordinated to a peroxide) configuration. Based on the formation energies, we find that mono-oxo moieties are the most stable among the three. This is also true for the moieties in the presence of hydroxyls on the support. Further, the computed vibrational frequencies of a mono-oxo moiety on a hydroxylated support is a closer match to the peaks observed in experiments. A thermodynamic analysis of the molybdenum oxide moieties on a hydroxylated support indicated that the dehydoxylation is favoured at high temperatures and low partial pressures of water. On adsorption of hydrogen on the oxygen of the support, hydrogen loses its electron and reduces Mo of the monomeric moiety without making an oxygen vacancy. We studied the activity of this reduced site for deoxygenation of anisole to benzene. The overall barriers for this reaction are comparable to previously computed barriers for deoxygenation of bio-oil model compounds on an oxygen-vacant molybdenum oxide surfaces, suggesting that this may be an important mechanistic pathway during a hydro-deoxygenation process.},
author = {Bose, Abir Lal and Ramteke, Sayali and Deo, Goutam and Agarwal, Vishal},
doi = {https://doi.org/10.1016/j.jcat.2023.115267},
journal = {Journal of Catalysis},
volume ={429},
pages = {115267},
publisher = {Elsevier Inc.},
title = {{Structures and Reactivity of Monomeric MoOx moieties Supported on ZrO2 (111) Slab: A DFT Study}},
url = {https://www.sciencedirect.com/science/article/pii/S0021951723005122},
year = {2024}
}