Premium
WO x ‐CeO 2 and WO x ‐Nb 2 O 5 catalysts deactivation during hexane isomerization
Author(s) -
Mamede A.S.,
Payen E.,
Granger P.,
Florea M.,
Pârvulescu V. I.
Publication year - 2008
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.11468
Subject(s) - catalysis , isomerization , oxalate , calcination , ammonium oxalate , chemistry , aqueous solution , ammonia , inorganic chemistry , incipient wetness impregnation , precipitation , hexane , niobium , analytical chemistry (journal) , organic chemistry , physics , meteorology , selectivity
Two series of WO x ‐CeO 2 catalysts containing 10, 12, and 15 wt % W were prepared by co‐precipitation and incipient wetness impregnation using a reported procedure. WO x ‐Nb 2 O 5 catalysts with the same amount of W were prepared by co‐precipitation starting from an aqueous solution of ammonium niobium oxalate and ammonium metatungstate with ammonia, until reaching pH 7. After calcining for 3 h in static air at 973 K, the deactivation of the catalysts was investigated using isomerization of hexane as probe reaction at temperatures in the range 393–513 K, both in the absence and in the presence of hydrogen. In‐situ Raman spectra during deactivation were recorded as well. The deactivation rate was fitted by an empirical Voorhies equation: R = m t −n , where the values of n correlated very well with the mass loss determined from TG analysis. © 2008 American Institute of Chemical Engineers AIChE J, 2008