The effect of V valence and P-V ratio on the activity and selectivity of V-P oxide catalysts for the oxidn. of 1-butene [106-98-9] to maleic anhydride (I) [108-31-6] is discussed. Chem. anal. and spectroscopy showed the oxidn. to involve redn. of V(IV) to V(III) in dehydrogenation of butene to butadiene [106-99-0], and redn. of V(V) in I formation from adsorbed butadiene. A slight excess of P stabilizes V(IV), avoiding excess formation of V(V) which affects the ratio of I formation and decompn. rates. Greater excesses of P slow the overall oxidn. of butene. A nonstoichiometric (biphase) catalyst structure maintains high concns. (≤20%) of V(V) and V(III) and an excess of P without formation of new cryst. phases, and so plays an important role in catalytic activity. [on SciFinder(R)]
Catalytic conversion of C4 hydrocarbons on vanadium-phosphorus oxides: factors influencing the selectivity in 1-butene oxidation
CENTI, Gabriele;
1985-01-01
Abstract
The effect of V valence and P-V ratio on the activity and selectivity of V-P oxide catalysts for the oxidn. of 1-butene [106-98-9] to maleic anhydride (I) [108-31-6] is discussed. Chem. anal. and spectroscopy showed the oxidn. to involve redn. of V(IV) to V(III) in dehydrogenation of butene to butadiene [106-99-0], and redn. of V(V) in I formation from adsorbed butadiene. A slight excess of P stabilizes V(IV), avoiding excess formation of V(V) which affects the ratio of I formation and decompn. rates. Greater excesses of P slow the overall oxidn. of butene. A nonstoichiometric (biphase) catalyst structure maintains high concns. (≤20%) of V(V) and V(III) and an excess of P without formation of new cryst. phases, and so plays an important role in catalytic activity. [on SciFinder(R)]Pubblicazioni consigliate
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