STEADY-STATE AND TRANSIENT REACTIVITY STUDY OF TIO2-SUPPORTED V2O5-WO3 DE-NOX CATALYSTS - RELEVANCE OF THE VANADIUM-TUNGSTEN INTERACTION ONTHE CATALYTIC ACTIVITY
L. Lietti et al., STEADY-STATE AND TRANSIENT REACTIVITY STUDY OF TIO2-SUPPORTED V2O5-WO3 DE-NOX CATALYSTS - RELEVANCE OF THE VANADIUM-TUNGSTEN INTERACTION ONTHE CATALYTIC ACTIVITY, Industrial & engineering chemistry research, 35(11), 1996, pp. 3884-3892
The reactivity of ternary V2O5-WO3/TiO2 de-NOx catalysts (V2O5 = 0-1.4
7% w/w, WO3 = 0-9% w/w) in the selective catalytic reduction (SCR) rea
ction is investigated under steady-state and transient conditions. The
results indicate that over the investigated catalysts the SCR reactio
n occurs via a redox mechanism and that the rate-determining step of t
he reaction is the catalyst reoxidation process. The reactivity of the
V2O5-WO3/TiO2 catalysts increases on increasing either the V2O5 or th
e WO3 loading; the reactivity of V and/or W in the ternary catalysts i
s higher than that of the corresponding binary samples. A synergism be
tween the TiO2-supported V and W surface oxide species in the SCR reac
tion is suggested, that is exploited in the enhancement of the catalys
t redox properties of the samples. Accordingly, tungsta increases the
rate of the SCR reaction of V2O5/TiO2 catalysts by favoring the cataly
st reoxidation by gas-phase oxygen.