TY - JOUR
T1 - Effect of Ba addition to Ga-Α-Al2O3 catalyst on structure and catalytic selectivity for dehydrogenation of ethane
AU - Seki, Hirofumi
AU - Saito, Hikaru
AU - Toko, Kenta
AU - Hosono, Yukiko
AU - Higo, Takuma
AU - Gil Seo, Jeong
AU - Maeda, Shun
AU - Hashimoto, Kunihide
AU - Ogo, Shuhei
AU - Sekine, Yasushi
N1 - Publisher Copyright:
© 2019 Elsevier B.V.
PY - 2019/7/5
Y1 - 2019/7/5
N2 - Modified Ga-α-Al2O3 catalyst with Ba showed high catalytic activity, selectivity and low carbon formation on catalytic ethane dehydrogenation to ethylene even in the presence of steam. The resultant Ba-Ga-α-Al2O3 (Ba/Ga molar ratio = 0.10) catalyst showed high ethylene selectivity (98%), high activity, and stability. Temperature-programmed oxidation measurements revealed that Ba addition suppressed coke formation at Ga sites. XRD, XAFS and TEM results showed the existence of highly dispersed β-Ga2O3 on the α-Al2O3 support, irrespective of Ba addition. Observation of hydrogen adsorption using FT-IR spectroscopy revealed a decrease in the surface tetrahedrally coordinated Ga (designated as Ga(T)) sites by Ba modification, indicating that the surface Ga(T) sites are covered with Ba. Density functional theory calculation revealed that coke formation through ethylene decomposition is likely to occur at surface Ga(T) sites, and revealed that the addition of an optimal amount of Ba to Ga-α-Al2O3 inhibits coke formation at the surface Ga(T) sites, leading to high ethylene selectivity.
AB - Modified Ga-α-Al2O3 catalyst with Ba showed high catalytic activity, selectivity and low carbon formation on catalytic ethane dehydrogenation to ethylene even in the presence of steam. The resultant Ba-Ga-α-Al2O3 (Ba/Ga molar ratio = 0.10) catalyst showed high ethylene selectivity (98%), high activity, and stability. Temperature-programmed oxidation measurements revealed that Ba addition suppressed coke formation at Ga sites. XRD, XAFS and TEM results showed the existence of highly dispersed β-Ga2O3 on the α-Al2O3 support, irrespective of Ba addition. Observation of hydrogen adsorption using FT-IR spectroscopy revealed a decrease in the surface tetrahedrally coordinated Ga (designated as Ga(T)) sites by Ba modification, indicating that the surface Ga(T) sites are covered with Ba. Density functional theory calculation revealed that coke formation through ethylene decomposition is likely to occur at surface Ga(T) sites, and revealed that the addition of an optimal amount of Ba to Ga-α-Al2O3 inhibits coke formation at the surface Ga(T) sites, leading to high ethylene selectivity.
KW - Ba addition
KW - Coke resistance
KW - Ethane dehydrogenation
KW - Ethylene selectivity
KW - Ga catalysts
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U2 - 10.1016/j.apcata.2019.05.008
DO - 10.1016/j.apcata.2019.05.008
M3 - Article
AN - SCOPUS:85066153288
SN - 0926-860X
VL - 581
SP - 23
EP - 30
JO - Applied Catalysis A: General
JF - Applied Catalysis A: General
ER -