Effect of Reaction Conditions on Ethane Oxidative Conversion over MoVTeNbO Catalyst
Oxidative dehydrogenation of C2-C3 alkanes is an interesting alternative to the current
industrial processes (steam cracking or catalytic dehydrogenation) for the olefins production.
At present, the most promising results are obtained for transformation of ethane to ethylene
 due to its lower reactivity as compared to propylene. The goal of the present study is
reveal of the reaction condition effects on the performance of MoVTeNbO catalyst in
oxidative conversion of ethane.
Oxide catalyst with the ratio Mo:V:Te:Nb = 1:0.3:0.23:0.12 have been prepared
according  by stepwise thermal decomposition of mixed slurry with formation of the socalled
M1 and M2 phases, the first being an active one . Catalytic activity has been carried
out at 340-480oC and varied mole ratio O2/C2H6 = 10.00.2 in flow and flow circulating setups
with on-line chromatographic analysis.
Formation of reaction products is described by triangular scheme with ethylene and
carbon oxides forming by parallel path from ethane and carbon oxides forming by
consecutive route from ethylene as well. Under O2/C2H6 1 within 340-460oC temperature
was determined does not affect the part of parallel and consecutive routes of reaction products
formation, therefore at equal ethane conversion selectivity to ethylene and COx are
independent of temperature. When ratio O2/C2H6 decreases up to 0.2 and reaction temperature
becomes higher then 470oC catalyst deactivation is observed. Decline in catalytic activity and
ethylene selectivity is conditioned by decomposition of M1 and M2 phases owing to partial
elimination of Te and Mo and formation of Te-free phases – Mo5-x(V,Nb)xO14 and (Mo,V)O2
possessing insufficient catalytic properties. On the basis of the dependencies of the rates of
particular reactions on reaction conditions kinetic model was proposed and kinetic parameters
were estimated with the maximal deviation of the calculated and experimental reaction
mixture concentrations of no more than 5.3%.