5
2
R.M. Blanco et al. / Catalysis Today 203 (2013) 48–52
In the case of VPO-S + 2M, it is important to emphasize that the
The modified samples demonstrated a higher catalytic activity
especially at higher n-butane concentrations in the feed, which cor-
responds to industrial reaction conditions in fluidized bed reactor
and circulating fluidized bed reactors. The proposed methodology
may be applicable to reactivate other catalytic formulations for
other reactions.
amount of vanadium (2 theoretical monolayers in the suspension)
into which the VPO-S catalyst was added is very small as com-
pared with the total amount of (VO) P O7 in the catalyst. If all the
2
2
vanadium deposited was converted to a (hypothetical) active VPO
phase, the weight of this phase would represent at most 3.6% of
the total weight of the VPO-S + 2M catalyst. However, since the
catalytic performance of VPO-S + 2M is slightly higher than that
of the in situ activated precursor, the surface of VPO-S could have
been reloaded with VPO species close to those of VOHPO ·0.5H O.
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4
2
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[
Firstly, the precursor and spent DuPont catalyst were submit-
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[
[
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2
cess iron oxide, excess phosphorous, and may be also certain forms
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[
1
[
[
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5 wt.% phosphoric acid was added to achieve 2 theoretical mono-
[
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[
Analyses showed that most detrimental oxide species were no
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+
4+
5+
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)
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