The kinetics of oxidative dehydrogenation of butene-2 to butadiene on the multiconponent molybdates catalyst

Mo12Bi1.5Fe3Co1Ni4.5Cr0.5K0.3/SiO2 (atomic ratio)

has been investigated in a flow-recirculation glass reactor. It was found that the butene conversion was m-order with respect to butene and n-order with respect to oxygen

m and n depended on the reaction temperature and concentration

m increased and n decreased with the rise of reaction temperature

and m+n=1. According to the steady state Redox mechanism: 1 ) The reduction of catalyst by butene and the reoxidation of reduced catalyst by oxygen were in steady state; 2 ) Butadiene reversibly adsorbed on the fraction of sites of the oxidized catalyst inhibited the butene conversion

the rate equation

was derived. The activation energy of catalyst reduction step E1 was 4.53 kcal/g-mole

the activation energies of catalyst reoxidation E2 were 21 kcal/ g-mole (>400℃) and 60 kcal/g-mole (<400℃). The Arrhenius figure of k2 appeared a broken-line and the turning point was at about 400℃.Under the condition of insignificant inhibition of butadiene

i. e. small partial pressure of butadiene or higher temperature

the above equation could simplify as: