TY - JOUR
T1 - Unravelling the pathway for the dehydrogenation of n-butane to 1,3-butadiene using thermodynamics and DFT studies
AU - Tanimu, Gazali
AU - Elmutasim, Omer
AU - Alasiri, Hassan
AU - Polychronopoulou, Kyriaki
N1 - Publisher Copyright:
© 2023 Elsevier Ltd
PY - 2023/10/5
Y1 - 2023/10/5
N2 - Dehydrogenation of n-butane is one of the main on-purpose method for producing 1,3- butadiene. Thermodynamics studies revealed that reasonable yields of 1,3-butadiene can only be achieved at higher temperatures, while the formation of butene isomers are favored at lower temperatures, confirming that 1,3-butadiene is a secondary product. In the present study, NiO/Al2O3 and Ni-BiOx/Al2O3 catalysts, having 10 and 20 wt% Ni and 10 and 30 wt% Bi loading were synthesized. Experimental testing using fixed bed reactor validated that the addition of BiOx improved 1,3-butadiene selectivity from 20 % to 43 % with similar n-butane conversion, at 500 °C. Also, density functional theory (DFT) studies for n-butane adsorption on Ni (1 1 1) and Bi-Ni (1 1 1) surfaces confirmed that, the addition of Bi promoters to the Ni surface modifies the n-butane adsorption strength resulting in lower adsorption energies of −0.02 eV weaker than −0.36 eV on Ni (1 1 1) surfaces. The reaction pathways investigation for the successive dehydrogenation route of n-butane on the most stable structures of Ni (1 1 1) and Bi-Ni (1 1 1) surfaces revealed that 1-butene pathway via the formation of 1-butyl, is most favorable relative to the 2-butene pathway via 2-butyl formation. This is due to the higher activation barrier for the formation of 2-butene intermediate on both Ni (1 1 1) and Bi-Ni (1 1 1) surfaces.
AB - Dehydrogenation of n-butane is one of the main on-purpose method for producing 1,3- butadiene. Thermodynamics studies revealed that reasonable yields of 1,3-butadiene can only be achieved at higher temperatures, while the formation of butene isomers are favored at lower temperatures, confirming that 1,3-butadiene is a secondary product. In the present study, NiO/Al2O3 and Ni-BiOx/Al2O3 catalysts, having 10 and 20 wt% Ni and 10 and 30 wt% Bi loading were synthesized. Experimental testing using fixed bed reactor validated that the addition of BiOx improved 1,3-butadiene selectivity from 20 % to 43 % with similar n-butane conversion, at 500 °C. Also, density functional theory (DFT) studies for n-butane adsorption on Ni (1 1 1) and Bi-Ni (1 1 1) surfaces confirmed that, the addition of Bi promoters to the Ni surface modifies the n-butane adsorption strength resulting in lower adsorption energies of −0.02 eV weaker than −0.36 eV on Ni (1 1 1) surfaces. The reaction pathways investigation for the successive dehydrogenation route of n-butane on the most stable structures of Ni (1 1 1) and Bi-Ni (1 1 1) surfaces revealed that 1-butene pathway via the formation of 1-butyl, is most favorable relative to the 2-butene pathway via 2-butyl formation. This is due to the higher activation barrier for the formation of 2-butene intermediate on both Ni (1 1 1) and Bi-Ni (1 1 1) surfaces.
KW - Adsorption
KW - Butene isomers
KW - Dehydrogenation
KW - DFT
KW - Thermodynamic studies
UR - http://www.scopus.com/inward/record.url?scp=85164324898&partnerID=8YFLogxK
U2 - 10.1016/j.ces.2023.119059
DO - 10.1016/j.ces.2023.119059
M3 - Article
AN - SCOPUS:85164324898
SN - 0009-2509
VL - 280
JO - Chemical Engineering Science
JF - Chemical Engineering Science
M1 - 119059
ER -