Non-lattice surface oxygen species implicated in the catalytic partial oxidation of decane to oxygen

Abstract

The one-step transformation of C7–C12 linear alkanes into more valuable oxygenates provides heterogeneous catalysis with a major challenge. In evaluating the potential of a classic mixed-metal-oxide catalyst, we demonstrate new insights into the reactivity of adsorbed oxygen species. During the aerobic gas-phase conversion of n-decane over iron molybdate, the product distribution correlates with the condition of the catalyst. Selectivity to oxygenated aromatics peaks at 350 °C while the catalyst is in a fully oxidized state, whereas decene and aromatic hydrocarbons dominate at higher temperatures. The high-temperature performance is consistent with an underlying redox mechanism in which lattice oxide ions abstract hydrogen from decane. At lower temperatures, the formation of oxygenated aromatics competes with the formation of CO2, implying that electrophilic adsorbed oxygen is involved in both reactions. We suggest, therefore, that so-called non-selective oxygen is capable of insertion into carbon-rich surface intermediates to generate aromatic partial oxidation products. Mixed-metal oxide catalysts oxidize hydrocarbons into CO and CO2 through surface oxygen species that have yet to form lattice oxide ions. The one-step oxidation of decane into a range of oxygenated aromatics by a fully oxidized iron molybdate catalyst has now revealed that these species can also be involved in selective oxygen insertion.

Cite this article

Pradhan, S., Bartley, J., Bethell, D. et al. Non-lattice surface oxygen species implicated in the catalytic partial oxidation of decane to oxygenated aromatics. Nature Chem 4, 134–139 (2012). https://doi.org/10.1038/nchem.1245

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