Influence of Tight Confinement on Selective Oxidative Dehydrogenation of Ethane on MoVTeNb Mixed Oxides
Autor: | Yilang Liu, Prashant Deshlahra, Yanliu Dang, Sopuruchukwu Ezenwa, Steven L. Suib, Leelavathi Annamalai |
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Rok vydání: | 2018 |
Předmět: |
Cyclohexane
Chemistry Vanadium chemistry.chemical_element 02 engineering and technology General Chemistry Activation energy 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Catalysis 0104 chemical sciences chemistry.chemical_compound Physical chemistry Dehydrogenation Density functional theory Reactivity (chemistry) 0210 nano-technology Selectivity |
Zdroj: | ACS Catalysis. 8:7051-7067 |
ISSN: | 2155-5435 |
Popis: | M1 phase MoVTeNb mixed oxides exhibit unique catalytic properties that lead to high C2H4 yields in oxidative conversion of C2H6 at moderate temperatures. The role of the heptagonal channel micropores of the M1 phase in regulating reactivity and selectivity is assessed here using reactant size-dependent kinetic probes and density functional theory (DFT) treatments for C2H6 and cyclohexane (C6H12) activations inside and outside the micropores. The sizes of C2H6 and the micropores suggest a tight guest–host fit, but C6H12 cannot access intrapore sites. Measured C2H6 to C6H12 activation rate ratios on MoVTeNbO are much higher than those measured on nonmicroporous vanadium oxides (VOx/SiO2) and estimated by DFT on external surfaces, suggesting that most C2H6 activations on MoVTeNbO occur inside the micropores under typical conditions. C2H6 exhibits higher activation energy than C6H12 on VOx/SiO2, consistent with the corresponding C–H bond strengths; the activation energy difference between C2H6 and C6H12 is lo... |
Databáze: | OpenAIRE |
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