Formation and Fate of Formaldehyde in Methanol-to-Hydrocarbon Reaction: In Situ Synchrotron Radiation Photoionization Mass Spectrometry Study |
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| Authors: | Wu Wen Shengsheng Yu Chaoqun Zhou Prof. Hao Ma Prof. Zhongyue Zhou Chuangchuang Cao Dr. Jiuzhong Yang Minggao Xu Prof. Fei Qi Prof. Guobin Zhang Prof. Yang Pan |
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| Affiliation: | 1. National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui, 230029 P. R. China;2. Key Laboratory for Power Machinery and Engineering of Ministry of Education, Shanghai Jiao Tong University, Shanghai, 200240 P. R. China |
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| Abstract: | HCHO has been confirmed as an active intermediate in the methanol-to-hydrocarbon (MTH) reaction, and is critical for interpreting the mechanisms of coke formation. Here, HCHO was detected and quantified during the MTH process over HSAPO-34 and HZSM-5 by in situ synchrotron radiation photoionization mass spectrometry. Compared with conventional methods, excellent time-resolved profiles were obtained to study the formation and fate of HCHO, and other products during the induction, steady-state reaction, and deactivation periods. Similar formation trends of HCHO and methane, and their close correlation in yields suggest that they are derived from disproportionation of methanol at acidic sites. In the presence of Y2O3, the amount of HCHO changes, affecting the hydrogen-transfer processes of olefins into aromatics and aromatics into cokes. The yield of HCHO affects the aromatic-based cycle and the formation of ethylene, indicating that ethylene is mainly formed from the aromatic-based cycle. |
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| Keywords: | Formaldehyd Massenspektrometrie Reaktionsmechanismen Oberflächenchemie Zeolithe |
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