Dehydrogenation of propane to propene over different polymorphs of gallium oxide
Dehydrogenation of propane to propene over different polymorphs of gallium oxide
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DOI：
10.1016/j.jcat.2005.03.001
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发表时间：
2005-05
影响因子：
7.3
通讯作者：
Bo Zheng;W. Hua;Y. Yue;Z. Gao
中科院分区：
文献类型：
--
作者：
Bo Zheng;W. Hua;Y. Yue;Z. Gao
研究了在存在或不存在 CO2 的情况下，四种氧化镓多晶型物上丙烷脱氢为丙烯的情况。 β-Ga2O3在多晶型物中表现出最高的活性，在CO2存在下其活性甚至比氧化铬催化剂还要高。 H2-TPR 和 XPS 研究表明，氧化镓在 600°C 以下几乎不被还原。脱氢反应通过异解解离反应途径进行，并且由于逆水煤气变换反应和布杜反应的存在，CO2 增强了脱氢反应。 β-Ga2O3的高催化活性可能与大量的表面中强酸位点有关，这些酸位点与配位不饱和Ga3+阳离子以及质子和氧化物的共轭效应有关。此外，提高反应温度有利于CO2对β-Ga2O3的活化。在550°C以上CO2对β-Ga2O3催化剂的促进作用更加明显。
Dehydrogenation of propane to propene in the presence or absence of CO2over four polymorphs of gallium oxide was investigated. β-Ga2O3exhibits the highest activity among the polymorphs, and it is even more active than chromium oxide catalyst in the presence of CO2. H2-TPR and XPS studies show that gallium oxide is hardly reduced below 600 °C. The dehydrogenation reaction is suggested to proceed through a heterolytic dissociation reaction pathway, and it is enhanced by CO2because of the existence of the reverse water gas shift reaction and the Boudouard reaction. The high catalytic activity of β-Ga2O3is probably associated with an abundance of surface medium-strong acid sites related to the coordinatively unsaturated Ga3+cations and the conjugated effect of proton and oxide. Furthermore, increasing the reaction temperature facilitates the activation of CO2over β-Ga2O3. The promoting effect of CO2on β-Ga2O3catalyst is more evident above 550 °C.