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Catalytic Ammonia Synthesis over Mo Nitride/ZSM‐5
Author(s) -
Liu Na,
Nie Lei,
Xue Nianhua,
Dong Houhuan,
Peng Luming,
Guo Xuefeng,
Ding Weiping
Publication year - 2010
Publication title -
chemcatchem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.497
H-Index - 106
eISSN - 1867-3899
pISSN - 1867-3880
DOI - 10.1002/cctc.200900155
Subject(s) - catalysis , ammonia , molybdenum , inorganic chemistry , nitride , zeolite , chemistry , dispersion (optics) , zsm 5 , nitrogen , ammonia production , organic chemistry , layer (electronics) , physics , optics
Molybdenum nitride species in HZSM‐5 are prepared by the reaction of ammonia with MoO x , which is pre‐exchanged into the channel of HZSM‐5. Both the processes of solid exchange of molybdenum oxide with the zeolite and the ammonia reaction are monitored by mass spectrometry. The Mo/N ratio of the MoN x species in the Mo nitride/HZSM‐5 is close to 2, as measured by temperature‐programmed oxidation. The MoN x species are more stable than bulk Mo 2 N against oxidation, due to the interaction between the molybdenum nitride species and the charged zeolite framework. The MoN x species, of which the dispersion is found to be greater than 90 %, are very active in ammonia synthesis and the catalytic activity is much more stable than that of bulk Mo 2 N. The reaction pressure is much more favorable to ammonia formation on the MoN x /ZSM‐5 catalyst than on bulk Mo 2 N. The interaction of nitrogen molecules with the inner electric field of the zeolite, at an equivalent pressure, enhances the reaction of ammonia synthesis.