TY - JOUR
T1 - Selective Conversion of Carbon Dioxide into Liquid Hydrocarbons and Long-Chain α-Olefins over Fe-Amorphous AlO xBifunctional Catalysts
AU - Khan, Muhammad Kashif
AU - Butolia, Paresh
AU - Jo, Heuntae
AU - Irshad, Muhammad
AU - Han, Daseul
AU - Nam, Kyung Wan
AU - Kim, Jaehoon
N1 - Publisher Copyright:
© 2020 American Chemical Society.
PY - 2020/9/18
Y1 - 2020/9/18
N2 - Considerable progress has been made in the conversion of carbon dioxide (CO2), which is highly thermodynamically stable, into liquid hydrocarbons using metal oxide/zeolite composite catalysts. Nevertheless, producing liquid hydrocarbons with a single catalyst without utilizing additional C-C coupling agents remains a formidable challenge. Herein, we report a bifunctional iron aluminum oxide (FeAlOx) catalyst that directly converts CO2 into C5+ hydrocarbons with an overall selectivity of 77.0% and CO2 conversion of 20.2% at a H2/CO2 ratio of 1:1. Notably, the selectivity for linear α-olefins (LAOs) was 52.4%, accounting for 78.4% of the total C4+ olefins. At a high H2/CO2 ratio of 3:1, the yield of C5+ hydrocarbons was 19.7%. The concept of crystalline-/amorphous-structured active sites in the single FeAlOx catalyst was proposed. The reducible magnetite (Fe3O4) phase, which contains surface oxygen vacancies, facilitated the reverse-water-gas-shift (RWGS) reaction to form CO via CO2 hydrogenation, and subsequent C-C coupling over Hägg iron carbide afforded lower olefins (C2-C4=). Long-chain LAOs were then formed on the surface of amorphous aluminum oxide (AlOx) via the readsorption of C2-C4=. In addition, the amorphous AlOx phase enhanced CO2 and H2 adsorption, which facilitated the formation of carbonate, bicarbonate, and formate species via the RWGS reaction and the subsequent formation of long-chain hydrocarbons via the Fischer-Tropsch reaction. The bifunctional FeAlOx catalyst showed excellent stability for up to 450 h on-stream, demonstrating its potential as a practical-scale catalyst for the conversion of CO2 into value-added liquid fuels and chemicals.
AB - Considerable progress has been made in the conversion of carbon dioxide (CO2), which is highly thermodynamically stable, into liquid hydrocarbons using metal oxide/zeolite composite catalysts. Nevertheless, producing liquid hydrocarbons with a single catalyst without utilizing additional C-C coupling agents remains a formidable challenge. Herein, we report a bifunctional iron aluminum oxide (FeAlOx) catalyst that directly converts CO2 into C5+ hydrocarbons with an overall selectivity of 77.0% and CO2 conversion of 20.2% at a H2/CO2 ratio of 1:1. Notably, the selectivity for linear α-olefins (LAOs) was 52.4%, accounting for 78.4% of the total C4+ olefins. At a high H2/CO2 ratio of 3:1, the yield of C5+ hydrocarbons was 19.7%. The concept of crystalline-/amorphous-structured active sites in the single FeAlOx catalyst was proposed. The reducible magnetite (Fe3O4) phase, which contains surface oxygen vacancies, facilitated the reverse-water-gas-shift (RWGS) reaction to form CO via CO2 hydrogenation, and subsequent C-C coupling over Hägg iron carbide afforded lower olefins (C2-C4=). Long-chain LAOs were then formed on the surface of amorphous aluminum oxide (AlOx) via the readsorption of C2-C4=. In addition, the amorphous AlOx phase enhanced CO2 and H2 adsorption, which facilitated the formation of carbonate, bicarbonate, and formate species via the RWGS reaction and the subsequent formation of long-chain hydrocarbons via the Fischer-Tropsch reaction. The bifunctional FeAlOx catalyst showed excellent stability for up to 450 h on-stream, demonstrating its potential as a practical-scale catalyst for the conversion of CO2 into value-added liquid fuels and chemicals.
KW - carbon dioxide hydrogenation
KW - diffuse reflectance infrared Fourier transform spectroscopy
KW - iron aluminum oxide
KW - linear α-olefins
KW - liquid fuels
KW - single catalyst
UR - http://www.scopus.com/inward/record.url?scp=85095448111&partnerID=8YFLogxK
U2 - 10.1021/acscatal.0c02611
DO - 10.1021/acscatal.0c02611
M3 - Article
AN - SCOPUS:85095448111
SN - 2155-5435
VL - 10
SP - 10325
EP - 10338
JO - ACS Catalysis
JF - ACS Catalysis
IS - 18
ER -