《Modulation mechanism of  Mn-O strength in α-MnO₂ catalyst for high-efficiency catalytic combustion of propane》

Website：https://doi.org/10.1016/j.apcatb.2024.124120

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Abstract：

The cleavage of C-H with high energy impedes the catalytic combustion of propane. Herein, α-MnO₂ with modulation of Mn-O strength by changing the calcination temperature was applied in propane catalytic combustion. α-MnO₂ calcinated at 350 ^oC (α-MnO₂-350) exhibited superior performance (T₂₀=150 ^oC, T₉₀= 220 ^oC) in propane oxidation due to the synergistic effect of oxygen vacancies (OVs) and Lewis acidity. Density functional theory (DFT) calculations revealed that the lowest o-vacancy formation energy on α-MnO₂-350 (E_vo=0.74 eV) with its lowest Mn-O strength prompted the existence of abundant OVs and propane oxidation. Moreover, the highest Lewis acidity in α-MnO₂-350 displayed the strongest propane adsorption, promoting the activation of C-H. The mineralization of propane on α-MnO₂-350 dropped steeply after 68 h while could recover to 90 % in long-term water vapor stability test owing to the H₂O adsorbed at OVs and the carbonaceous intermediates adsorbed at the Lewis acid sites.