The selective oxidation of propane on Mo-V-Te-Nb-O catalysts: The influence of Te-precursor
The selective oxidation of propane on Mo-V-Te-Nb-O catalysts: The influence of Te-precursor
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Mo-V-Te-Nb-O 催化剂上丙烷的选择性氧化：Te 前体的影响
DOI：
10.1016/s0920-5861(03)00119-6
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发表时间：
2003
期刊：
影响因子：
5.3
通讯作者：
J. Oliver
中科院分区：
文献类型：
--
作者：
J. Nieto;P. Botella;B. Solsona;J. Oliver
采用水热合成法制备了Mo-V-Te-Nb-O催化剂，并将其用于丙烷选择氧化制丙烯酸反应。通过使用不同的Te-和Mo-起始化合物制备催化剂。催化剂表征结果（XRD、SEM-EDX、FTIR和XPS）和催化测试都显示出取决于水热合成中使用的Te-和Mo-起始化合物的重要差异。用于丙烷氧化成丙烯酸的最具活性和选择性的催化剂是由Te（VI）-化合物，即碲酸或Anderson型碲酸盐制备的那些。然而，由Te（IV）-化合物（TeO 2或（NH 4）4 TeMo 6 O22·2 H2O）制备的催化剂活性和丙烯酸选择性均较低。在最佳催化剂中，观察到了几种晶相：Mo 5 TeO_（16），（Mo_（0.93）V_（0.07））_5O_（14）和/或Nb_（0.09）Mo_（0.91）O_（2.80）以及新的Te-V-Nb-Mo-氧化物晶相。也可以提出MoO 3小晶体在活性和选择性催化剂中的存在。这些催化剂的不同催化性能可能与Te、V和Nb离子的不同掺入有关，这强烈依赖于合成凝胶中引入的Te化合物。
Mo-V-Te-Nb-O catalysts have been prepared by hydrothermal synthesis and have been tested in the selective oxidation of propane to acrylic acid. The catalysts have been prepared by using different Te- and Mo-starting compounds. Both the catalyst characterization results (XRD, SEM–EDX, FTIR and XPS) and the catalytic tests show important differences depending on the Te- and Mo-starting compounds used in the hydrothermal synthesis. The most active and selective catalysts for the oxidation of propane to acrylic acid were those prepared from Te(VI)-compounds, i.e. telluric acid or an Anderson-type telluromolybdate. However, catalysts prepared from Te(IV)-compounds, i.e. TeO2or (NH4)4TeMo6O22·2H2O, presented both low activity and low selectivity to acrylic acid. In the best catalysts, several crystalline phases were observed: Mo5TeO16, (Mo0.93V0.07)5O14, and/or Nb0.09Mo0.91O2.80and new Te-V-Nb-Mo-oxide crystalline phases. The presence of small crystals of MoO3in active and selective catalysts can also be proposed. The different catalytic performance of these catalysts could be related to the different incorporation of Te, V and Nb ions, which depends strongly on the Te-compound introduced in the synthesis gel.