Partial oxidation of methanol to formaldehyde over molybdenum oxide on silica
Partial oxidation of methanol to formaldehyde over molybdenum oxide on silica
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DOI：
10.1016/0021-9517(87)90092-3
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发表时间：
1987
影响因子：
7.3
通讯作者：
Tsong‐Jen Yang;J. Lunsford
中科院分区：
文献类型：
--
作者：
Tsong‐Jen Yang;J. Lunsford
发现负载在高表面积二氧化硅上的氧化钼对于甲醇部分氧化成甲醛是活性的，但不是特别选择性的催化剂。N2O作为氧化剂的活性和选择性都大大低于O2。这一观察结果表明，O−离子，来自N2O，不参与CH3OH的活化，但它们可能是重要的HCHO和CO的氧化。初始活性与催化剂在部分还原状态，这支持MoIV的作用，以及MoV和MoVI在氧化还原循环中的作用。同样，有人发现，在几个未负载的氧化物和羟基氧化物，Mo2O5具有最大的活性，甲醛的形成。动力学同位素效应的研究证实了早期的观察，即甲基中的C → H键的断裂是催化循环中的缓慢步骤。
Molybdenum oxide supported on high surface area silica was found to be an active, though not a particularly selective catalyst for the partial oxidation of methanol to formaldehyde. Both the activity and selectivity with N2O as the oxidant were considerably less than with O2. This observation suggests that O−ions, derived from N2O, are not involved in the activation of CH3OH, but they may be important in the oxidation of HCHO and CO. The initial activity was greater with the catalyst in a partially reduced state, which lends support to the role of MoIV, as well as MoVand MoVIin the redox cycle. Similarly, it was found that among several unsupported oxides and an oxyhydroxide, Mo2O5had the greatest activity for the formation of formaldehyde. Kinetic isotope effect studies confirm an earlier observation that the breaking of CH bonds in the methyl group is the slow Step in a Catalytic cycle.