Abstract
Hierarchically concerted effect of acid-base cohabitation over ternary metal (Ni-Fe-Co)-Bi-O/Al2O3 catalysts on oxidative dehydrogenation of n-butane (C40) to butadiene (C42). ▪
•The performance of catalysts for ODH reactions depends on metal species composition.•Partial substitution of Ni with Fe or Co improves Ni-Bi-O/Al2O3 catalytic effect.•Partial Fe substitution up to 50% improves butadiene selectivity.•Partial Co substitution up to 50% improves n-butane conversion.•Partial substitution of Ni with Fe and Co improves both activity and selectivity.•Partial substitution of Fe and Co changes the catalyst acidic/basic character.
The effect of metal oxide species in (Ni, Fe and/or Co) oxide-Bi2O3 over gamma-alumina support was investigated for n-butane oxidative dehydrogenation. Partial substitution of Ni up to 50% by Fe improved butadiene selectivity while same substitution with Co increased n-butane conversion. The ternary Ni-Fe-Co system (10wt% Ni–5wt% Fe–5wt% Co–30wt% Bi-O/gamma-Al2O3) showed the highest butadiene selectivity of 46.3% at n-butane conversion of 30%. The acid-base sites preferably adjusted by ternary main metal combination in hierarchical cohabitation of metal (Ni, Fe and Co) oxide, Bi2O3 and gamma-Al2O3 cooperate to accelerate butadiene selectivity at both 1st and 2nd step dehydrogenations due to an increased H2 abstraction and 1-butene intermediate adsorption.