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Title: The mechanism and kinetics of propene ammoxidation over α-bismuth molybdate

Propene ammoxidation over Bi 2Mo 3O 12 was investigated to elucidate product (acrylonitrile, acetonitrile, HCN, acrolein, N 2, etc.) formation pathways. Propene consumption rate is first order in propene and zero order in ammonia (for NH 3/C 3H 6 = 0-2) and oxygen (for O 2 /C 3 H 6 ≥ 1.5) partial pressures, with an activation energy (E a = 22 kcal/mol) comparable to that for propene oxidation, suggesting the same rate-limiting step for both reactions. We propose two N-containing species are relevant at ammoxidation conditions: adsorbed NH 3 on surface Bi 3+ ions that reacts with a propene derivative to form products with C-N bonds, and a few metastable M-NH x (M = Mo, Bi; x = 1, 2) groups that are very sensitive to destruction by water, but that are responsible for NH 3 oxidation to N 2. A proposed reaction mechanism and model that captures the experimental trends in product distribution as a function of partial pressures and temperature are presented.
Authors:
 [1] ;  [1] ;  [1]
  1. Univ. of California, Berkeley, CA (United States). Dept. of Chemical and Biomolecular Engineering
Publication Date:
Grant/Contract Number:
AC02-05CH11231; CHE-0840505
Type:
Accepted Manuscript
Journal Name:
Journal of Catalysis
Additional Journal Information:
Journal Volume: 339; Journal ID: ISSN 0021-9517
Publisher:
Elsevier
Research Org:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org:
SC-22.1 USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Chemical Sciences, Geosciences & Biosciences Division; USDOE
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Bismuth molybdate; Selective ammoxidation; Propene; Ammonia; Acrylonitrile
OSTI Identifier:
1418290
Alternate Identifier(s):
OSTI ID: 1341150