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Heterogeneous Partial (amm)Oxidation and Oxidative Dehydrogenation Catalysis on Mixed Metal Oxides

机译：混合金属氧化物的异质部分（amm）氧化和氧化脱氢催化

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This paper presents an overview of heterogeneous partial (amm)oxidation and oxidative dehydrogenation (ODH) of hydrocarbons. The review has been voluntarily restricted to metal oxide-type catalysts, as the partial oxidation field is very broad and the number of catalysts is quite high. The main factors of solid catalysts for such reactions, designated by Grasselli as the “seven pillars”, and playing a determining role in catalytic properties, are considered to be, namely: isolation of active sites (known to be composed of ensembles of atoms), Me–O bond strength, crystalline structure, redox features, phase cooperation, multi-functionality and the nature of the surface oxygen species. Other important features and physical and chemical properties of solid catalysts, more or less related to the seven pillars, are also emphasized, including reaction sensitivity to metal oxide structure, epitaxial contact between an active phase and a second phase or its support, synergy effect between several phases, acid-base aspects, electron transfer ability, catalyst preparation and activation and reaction atmospheres, etc. Some examples are presented to illustrate the importance of these key factors. They include light alkanes (C 1 –C 4 ) oxidation, ethane oxidation to ethylene and acetic acid on MoVTe(Sb)Nb-O and Nb doped NiO, propene oxidation to acrolein on BiMoCoFe-O systems, propane (amm)oxidation to (acrylonitrile) acrylic acid on MoVTe(Sb)Nb-O mixed oxides, butane oxidation to maleic anhydride on VPO: (VO) 2 P 2 O 7 -based catalyst, and isobutyric acid ODH to methacrylic acid on Fe hydroxyl phosphates. It is shown that active sites are composed of ensembles of atoms whose size and chemical composition depend on the reactants to be transformed (their chemical and size features) and the reaction mechanism, often of Mars and van Krevelen type. An important aspect is the fact that surface composition and surface crystalline structure vary with reaction on stream until reaching steady state, which makes characterisation of active and selective surface sites quite difficult. The use of oxidants other than O 2 , such as H 2 O 2 , N 2 O or CO 2 , is also briefly discussed. Based on such analysis and recent discoveries and process developments, our perspective is given.
机译：本文概述了碳氢化合物的异质部分（氨）氧化和氧化脱氢（ODH）。由于部分氧化领域非常广泛并且催化剂的数量非常多，因此该评论被自愿限制为金属氧化物型催化剂。被认为是此类反应的固体催化剂的主要因素，被格拉斯利（Grasselli）称为“七个支柱”，并且在催化性能中起着决定性的作用，即：分离活性位点（已知由原子团组成） ，Me-O键强度，晶体结构，氧化还原特性，相合作，多功能性和表面氧物种的性质。固体催化剂的其他重要特征和物理化学性质或多或少都与七个支柱有关，还包括对金属氧化物结构的反应敏感性，活性相与第二相或其载体之间的外延接触，几个阶段，酸碱方面，电子转移能力，催化剂的制备以及活化和反应气氛等。给出一些实例来说明这些关键因素的重要性。它们包括轻烷烃（C 1 -C 4）氧化，在MoVTe（Sb）Nb-O和Nb掺杂的NiO上乙烷氧化为乙烯和乙酸，在BiMoCoFe-O系统上将丙烯氧化为丙烯醛，在丙烷（amm）氧化为（ MoVTe（Sb）Nb-O混合氧化物上的丙烯腈）丙烯酸，VPO：（VO）2 P 2 O 7基催化剂上的丁烷氧化为顺丁烯二酸酐，Fe羟基磷酸盐上的异丁酸ODH为甲基丙烯酸。结果表明，活性位是由原子的集合组成的，原子的大小和化学组成取决于待转化的反应物（其化学性质和大小特征）和反应机理，通常为火星和范·克雷维伦类型。一个重要的方面是这样的事实，即表面组成和表面晶体结构会随着流中反应的变化而变化，直到达到稳态为止，这使得表征活性和选择性表面位点非常困难。还简要讨论了使用除O 2以外的其他氧化剂，例如H 2 O 2，N 2 O或CO 2。基于这样的分析以及最近的发现和过程发展，我们给出了观点。

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