Chinese Journal of Catalysis

Chinese Journal of Catalysis ›› 2010, Vol. 31 ›› Issue (7): 729-738.

• Articles • Previous Articles     Next Articles

Stability Enhancement of H-Mordenite in Dimethyl Ether Carbonylation to Methyl Acetate by Pre-adsorption of Pyridine

LIU Junlong1, XUE Huifu1, HUANG Xiumin1, WU Pei-Hao2, HUANG Shing-Jong3, LIU Shang-Bin2,*, SHEN Wenjie1,#   

  1. 1State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China 2Institute of Atomic and Molecular Sciences, “Academia Sinica”, Taipei 10617, Taiwan, China 3Department of Chemistry, Taiwan University, Taipei 10617, Taiwan, China
  • Received:2010-07-25 Online:2010-07-25 Published:2010-07-25

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Abstract: The carbonylation of dimethyl ether to methyl acetate over H-mordenite (HMOR) and pyridine-modified HMOR was compared. The catalytic stability of HMOR was improved significantly by pyridine pre-adsorption, and a yield of methyl acetate ~30% was still obtained after 48 h on stream at 473 K. In situ infrared spectroscopy and ammonia temperature-programmed desorption revealed that pyridine prefer-entially occupied the acidic sites in 12-membered ring pores but not the acidic sites in 8-membered ring pores. 129Xe NMR studies suggested that the channels of HMOR were blocked by coke in the reaction but those in the pyridine-modified HMOR were not. The acidic sites in the 12-membered ring pores were responsible for the deactivation of HMOR, and the reaction can be directed to occur mainly on the acidic sties in the 8-membered ring pores by the selective adsorption of pyridine in the 12-membered ring pores.

Key words: dimethyl ether, carbonylation, methyl acetate, H-mordenite, pyridine, stability