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[资源] Science最新文章：钼氧化物催化甲烷直接转化为芳香族化合物

从分子尺度上认识Mo nanostructures/ZSM-5复合催化剂及其在反应过程中结构的转化是制约甲烷直接转化反应的瓶颈。美国斯蒂文理工学院和里海大学研究者将Mo氧化物负载于ZSM-5分子筛中，结合DFT密度泛函理论研究和多种原位分析技术（In situ UV-vis DRS，In situ IR，和operando Raman光谱），确定了钼氧化物的初始锚定位点并明确了催化剂结构与催化活性间的关系。反应过程中，钼氧化物催化剂发生聚集并转化为碳化钼，借助氧气可以活化再生钼氧化物催化剂，通过调节氧处理过程可以控制钼氧化物催化剂的分散状况，从而进一步提高催化性能。

Abstract：Direct methane conversion into aromatic hydrocarbons over catalysts with Mo nanostructures supported on shape selective zeolites is a promising chemistry for natural gas liquefaction. We determined the identity and anchoring sites of the initial Mo structures in such catalysts as isolated oxide species with a single Mo atom on Al sites in the zeolite framework and on Si sites on the zeolite external surface. During the reaction, the initial isolated Mo oxide species agglomerate and convert into carbided Mo nanoparticles. This process is reversible, and the initial isolated Mo oxide species can be restored by a treatment with gas-phase oxygen. Furthermore, the distribution of the Mo nanostructures can be controlled and catalytic performance can be fully restored, and even enhanced, by adjusting the oxygen treatment.

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