Chen Zhiyang, Ni Youming, Zhi Yuchun, Wen Fuli, Zhou Ziqiao, Wei Yingxu, Zhu Wenliang, Liu Zhongmin
National Engineering Laboratory for Methanol to Olefins, Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, P. R. China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Angew Chem Int Ed Engl. 2018 Sep 17;57(38):12549-12553. doi: 10.1002/anie.201807814. Epub 2018 Aug 28.
The conversion of methanol into aromatics over unmodified H-ZSM-5 zeolite is generally not high because the hydrogen transfer reaction results in alkane formation. Now circa 80 % aromatics selectivity for the coupling reaction of methanol and carbon monoxide over H-ZSM-5 is reported. Carbonyl compounds and methyl-2-cyclopenten-1-ones (MCPOs), which were detected in the products and catalysts, respectively, are considered as intermediates. The latter species can be synthesized from the former species and olefins. C isotope tracing and C liquid-state NMR results confirmed that the carbon atoms of CO molecules were incorporated into MCPOs and aromatic rings. A new aromatization mechanism that involves the formation of the above intermediates and co-occurs with a dramatically decreased hydrogen transfer reaction is proposed. A portion of the carbons in CO molecules are incorporated into aromatic, which is of great significance for industrial applications.
在未改性的H-ZSM-5沸石上，甲醇转化为芳烃的转化率通常不高，因为氢转移反应会导致烷烃生成。目前有报道称，在H-ZSM-5上甲醇与一氧化碳的偶联反应的芳烃选择性约为80%。分别在产物和催化剂中检测到的羰基化合物和甲基-2-环戊烯-1-酮（MCPOs）被认为是中间体。后一种物质可以由前一种物质和烯烃合成。碳同位素追踪和碳液态核磁共振结果证实，CO分子的碳原子被纳入MCPOs和芳环中。提出了一种新的芳构化机制，该机制涉及上述中间体的形成，并且与显著降低的氢转移反应同时发生。CO分子中的一部分碳被纳入芳烃中，这对工业应用具有重要意义。
