Methyl Acetate Synthesis from Dimethyl Ether Carbonylation over Mordenite Modified by Cation Exchange

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• 作者：Shurong Wang ; Wenwen Guo ; Lingjun Zhu ; Haixia Wang ; Kunzan Qiu ; Kefa Cen
• 刊名：Journal of Physical Chemistry C
• 出版年：2015
• 出版时间：January 8, 2015
• 年：2015
• 卷：119
• 期：1
• 页码：524-533
• 全文大小：630K
• ISSN：1932-7455

文摘

Various metal-modified HMOR catalysts for the carbonylation of dimethyl ether (DME) were prepared by ion exchange with Cu, Ni, Co, Zn, or Ag. The catalysts were characterized by the Brunauer鈥揈mmett鈥揟eller method, X-ray diffraction measurements, transmission electron microscopy, X-ray photoelectron spectroscopy, nuclear magnetic resonance spectroscopy, temperature-programmed desorption of ammonia, and temperature-programmed oxidation. We found that the pore structure of mordenite (HMOR) was well maintained and that the metal species were highly dispersed on the zeolite. On HMOR subjected to ion exchange with Cu, Ni, Co, or Zn, the metal ions were mainly at the zeolite exchange sites with some corresponding metal oxides. Some Br酶nsted acid sites were converted to Lewis acid sites, and some strong acid sites were formed together. HMOR modified with Cu, Ni, or Co showed good catalytic performance, with Cu/HMOR exhibiting the highest performance. DME conversion and methyl acetate selectivity were close to 100% under the optimum reaction conditions, which is attributed to the joint participation of Br酶nsted acid sites contributing to DME conversion and metal Lewis acid sites contributing to CO binding, along with the appropriate coordination structure. Modification with Cu not only improved the catalytic activity, but also suppressed carbon deposition and extended the catalyst lifetime.