Abstract

Molecular metal oxide cluster, K₅[α-1,2-PV₂W₁₀O₄₀] (PV₂W₁₀), was found to have intrinsic catalytic activity for the oxidative dehydrogenation of propane with high selectivity (> 80%) to propylene at low propane conversion (0.3%). Synthesis of dispersed PV₂W₁₀ in non-reducible supports, γ-Al₂O₃ and SiO₂, was done by incipient wetness impregnation. The supported catalysts were characterized by IR, Raman spectroscopy, nitrogen adsorption, x-ray powder diffraction (PXRD), elemental analysis, hydrogen temperature-programmed reduction (H₂–TPR), and ammonia temperature-programmed desorption (NH₃–TPD). Catalytic testing of the supported PV₂W₁₀ at equimolar cluster concentration revealed that when supported in γ-Al₂O₃ it is more active (sevenfold increase in propane conversion) but in SiO₂ it is more selective to propylene (94%). The observed performance was due to both an increase in reducibility and higher concentration of strong acid sites for PV₂W₁₀ supported in γ-Al₂O₃ versus SiO₂. Lastly, PV₂W₁₀ was shown to remain intact under reaction conditions indicating its thermal and oxidative stability.

Graphic abstract

中文翻译：

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不可还原载体-Al 2 O 3和SiO 2上的二钒取代的乞金[PV 2 W 10 O 40]：丙烷的氧化脱氢的合成，表征和催化性能

摘要

分子金属氧化物簇，K ₅ [α-1,2-PV ₂ W ^ ₁₀ ø ₄₀ ]（PV ₂ w ^ ₁₀），被发现具有用于丙烷的高选择性（> 80％）的氧化脱氢固有的催化活性以低丙烷转化率（0.3％）的丙烯。分散PV的合成₂ w ^ ₁₀在非还原性载体，在γ-Al ₂ ö ₃和SiO ₂，通过初湿含浸法进行。通过红外光谱，拉曼光谱，氮吸附，X射线粉末衍射（PXRD），元素分析，氢气程序升温还原（H ₂–TPR）和程序升温的氨解吸（NH ₃ –TPD）。所支持的PV的催化测试₂ w ^ ₁₀以等摩尔簇浓度透露，在支持时的γ-Al ₂ ö ₃更有效（在丙烷的转化七倍增加），但以SiO ₂更选择性的丙烯（94％）。所观察到的性能，是由于二者的增加还原性的光伏强酸位较高浓度₂ w ^ ₁₀支撑在γ-Al系₂ ö ₃对比的SiO ₂。最后，PV ₂ W ₁₀ 可见在反应条件下仍保持完整，表明其热和氧化稳定性。

图形摘要