TY - JOUR
T1 - Fischer-Tropsch synthesis
T2 - Mössbauer investigation of iron containing catalysts for hydrogenation of carbon dioxide
AU - Gnanamani, Muthu Kumaran
AU - Jacobs, Gary
AU - Hamdeh, Hussein H.
AU - Shafer, Wilson D.
AU - Davis, Burtron H.
PY - 2013/5/30
Y1 - 2013/5/30
N2 - CO2 hydrogenation was investigated with a doubly promoted (Cu, K) silica containing iron catalyst. Hägg carbide (χ-Fe 5C2) is the dominant phase obtained under CO activation conditions at 543 K and 0.1 MPa and it was stable under FTS conditions typical for coal or biomass derived syngas using a H2/CO ratio of 1:1 for at least ∼100 h TOS. An Fe-phase change occurs (χ-Fe5C 2 → Fe3O4) after switching from H 2:CO:N2 (1:1:2) to H2:CO2 (3:1). The distribution of hydrocarbon products changes significantly after switching to H2:CO2 (3:1), but then it slowly transformed to normal FTS products, albeit with over 3 times higher methane selectivity compared to FTS using H2:CO:N2 (1:1:2). A correlation was obtained between the rate of FTS and the % of Fe carbide indicating that iron carbide is the active phase for CO2-based FT synthesis. Irrespective of conditions (i.e., either H2:CO:N2 = 1:1:2 or H2:CO 2 = 3:1) and the Fe phase, the methane selectivity appears to primarily depend on the H2/CO ratio.
AB - CO2 hydrogenation was investigated with a doubly promoted (Cu, K) silica containing iron catalyst. Hägg carbide (χ-Fe 5C2) is the dominant phase obtained under CO activation conditions at 543 K and 0.1 MPa and it was stable under FTS conditions typical for coal or biomass derived syngas using a H2/CO ratio of 1:1 for at least ∼100 h TOS. An Fe-phase change occurs (χ-Fe5C 2 → Fe3O4) after switching from H 2:CO:N2 (1:1:2) to H2:CO2 (3:1). The distribution of hydrocarbon products changes significantly after switching to H2:CO2 (3:1), but then it slowly transformed to normal FTS products, albeit with over 3 times higher methane selectivity compared to FTS using H2:CO:N2 (1:1:2). A correlation was obtained between the rate of FTS and the % of Fe carbide indicating that iron carbide is the active phase for CO2-based FT synthesis. Irrespective of conditions (i.e., either H2:CO:N2 = 1:1:2 or H2:CO 2 = 3:1) and the Fe phase, the methane selectivity appears to primarily depend on the H2/CO ratio.
KW - CO hydrogenation
KW - Fischer-Tropsch synthesis
KW - Hägg carbide
KW - Iron catalysts
KW - Mössbauer
UR - http://www.scopus.com/inward/record.url?scp=84876752160&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84876752160&partnerID=8YFLogxK
U2 - 10.1016/j.cattod.2012.02.059
DO - 10.1016/j.cattod.2012.02.059
M3 - Article
AN - SCOPUS:84876752160
SN - 0920-5861
VL - 207
SP - 50
EP - 56
JO - Catalysis Today
JF - Catalysis Today
ER -