Effect of A12O3 Binder on the Precipitated Iron-Based Catalysts for Fischer-Tropsch Synthesis

Wan, Haijun; Wu, Baoshan; An, Xia; Li, Ting-Zhen; Tao, Zhichao; Xiang, Huimin; Li, Yongwang

doi:10.1016/s1003-9953(07)60038-3

Cited by 32 publications

(17 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…4, the Ir/Al 2 O 3 presents a major reduction peak at around 90°C and a minor peak centering at 240°C, which could be ascribed to the reduction of IrO 2 with different sizes [16]. For the FeO x /Al 2 O 3 , two broad reduction peaks occurring at 360°C and 620°C are observed, which were due to the reduction of Fe 3+ to Fe 2+ and further to Fe 0 [17]. In comparison with the Ir/Al 2 O 3 , the three Fe-promoted Ir/Al 2 O 3 catalysts are characterized with a very strong reduction peak at 100*200°C, which should be an overlap of the reduction of both Ir 4+ and Fe 3+ according to the large consumption amount of H 2 .…”

Section: Catalytic Activity Testsmentioning

confidence: 85%

Promoting Role of Fe in the Preferential Oxidation of CO Over Ir/Al2O3

Zhang

Wang

et al. 2007

Catal Lett

View full text Add to dashboard Cite

A novel catalyst Ir-FeO x /Al 2 O 3 designed for the preferential oxidation (PROX) of CO under excess hydrogen was developed in this work. To clarify the promoting role of Fe species, three different impregnation sequences were employed, and the resultant catalysts were characterized by various techniques. The results showed that the Ir-FeO x /Al 2 O 3 catalyst, which was prepared by the co-impregnation procedure, exhibited the best performance for the PROX. The partially exposed and highly dispersed Ir sites and the FeO x sites allowed good adsorption for both CO and O 2 over the Ir-FeO x /Al 2 O 3 , which was believed to be responsible for the enhanced activity.

show abstract

Section: Catalytic Activity Testsmentioning

confidence: 85%

Promoting Role of Fe in the Preferential Oxidation of CO Over Ir/Al2O3

Zhang

Wang

et al. 2007

Catal Lett

View full text Add to dashboard Cite

show abstract

“…Hägg carbide was not detected in the 15 and 15/0.6 catalysts even at 280 8Ca ccording to the LCF (Supporting Information, Figure S6), which can be ascribed to the strong Fe-Al 2 O 3 interaction [31][32][33] and subsequent lack of metallic Cu nucleation sites to promote iron carburization. Twor eduction steps were observed;a rapid step at 230 8Cf ollowed by as lows tep at 250-280 8C.…”

Section: Fischer-tropsch Synthesis In Af Ixed-bed Reactormentioning

confidence: 99%

“…[13] Asimilarprofile was observed for the catalyst containing 0.6 wt %o fC ub ut the peaks were shifted to lower temperatures, indicating that also low Cu loading promotes the iron reduction.T he TPR profiles of the 15/2 and 15/5 catalystss howedanarrow peak gradually shifted to lower temperature with increasing Cu loading. [31][32][33] It is known that Fe/Al 2 O 3 catalysts undergoi ron phase transformations, that is, Fe 2 O 3 !Fe 3 O 4 !FeO!Fe 0 ,b ut the reduction of FeO to metallici ron is hindered because the FeO phase (metastable phase of iron oxide below 570 8C) can be stabilised on Al 2 O 3 , [66] whichc ould furtherr etard reduction to Fe 0 .A ccording to these results, the reduction to Fe 0 is still difficult due to the interaction of FeO with the aluminas upport, but the addition of Cu promotes the reduction of hematite to wustite. Distinguishing between the reduction of iron and copper oxides by TPR was not possible.This may suggest intimate contact between Cu and Fe particles, as the combined reduction of CuO!Cu and Fe 2 O 3 !Fe 3 O 4 has been reported.…”

Section: Characterisation Of Fresh Catalystsmentioning

confidence: 99%

“…20-22 %) even at high Cu loading. [16,26,[30][31][32][33][34] Wane tal. After exposing the spent catalysts to hydrogenation conditions, the carboxylate species remained strongly adsorbed whilea liphatic hydrocarbonsa nd formate speciesd isappeared.T he accumulation of oxygenates species on the catalysts urfacei ncreased with Cu loading.…”

Section: Introductionmentioning

confidence: 99%

“…[21] Supported iron catalysts show better catalytic stability [31] owing to improved resistance towards attritiona nd sintering especially SiO 2 and Al 2 O 3 as supports. [16,26,[30][31][32][33][34] Wane tal. [33] reported that SiO 2 suppressesH 2 adsorption, facilitates CO adsorption, iron carburization, and selectivity to heavierhydrocarbons, leading to more active catalysts comparedt oA l 2 O 3 , [35] althought he run stability of Fe/Al 2 O 3 catalysts is generally better than Fe/SiO 2 analogues.d eS mit et al [16] have reported strong interaction between Fe 2 + (Fe 1Àx O) species and the SiO 2 support, leading to formation of iron(II) silicate (Fe 2 SiO 4 )s pecies.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The Effect of Copper Loading on Iron Carbide Formation and Surface Species in Iron‐Based Fischer–Tropsch Synthesis Catalysts

et al. 2018

View full text Add to dashboard Cite

The effect of copper as promoter on iron carbide formation and the nature of surface species on iron‐based catalyst during Fischer–Tropsch synthesis (FTS) was investigated. Iron‐based catalysts (15 wt % of Fe) supported on alumina promoted with copper (0, 0.6, 2, and 5 wt %) were characterised in situ at relevant FTS conditions. The catalysts promoted with 2 and 5 wt % of Cu showed higher catalytic activity due to the formation of Hägg carbide (Fe5C2) detected by in situ XANES and XRD. The carbide formation is attributed to a weakening of the iron–alumina mixed‐compound interactions, and hence increasing iron reducibility and dispersion. The in situ XANES measurements indicated a maximum carburization degree (ca. 20–22 %) even at high Cu loading. The catalyst promoted with 5 wt % of Cu exhibited higher water‐gas shift activity. Aliphatic hydrocarbons, formate, and carboxylate species were detected on the catalyst surface during FTS. After exposing the spent catalysts to hydrogenation conditions, the carboxylate species remained strongly adsorbed while aliphatic hydrocarbons and formate species disappeared. The accumulation of oxygenates species on the catalyst surface increased with Cu loading. The interaction of oxygenates with alumina and iron oxide particles (FexOy) were revealed, with the latter being a possible reason for inhibition of further iron carburization.

show abstract

Fischer–Tropsch Synthesis Over Skeletal FeCe Catalysts Leached from Rapidly Quenched Ternary FeCeAl Alloys

Sun¹,

Lin²,

Xu³

et al. 2013

ChemCatChem

View full text Add to dashboard Cite

The new Ce‐promoted skeletal Fe catalysts with different Ce contents were prepared through alkali leaching of rapidly quenched ternary FeCeAl alloys and evaluated in the gas‐phase Fischer–Tropsch synthesis reaction. N2 physisorption and XRD analysis confirmed the function of Ce as a structural promoter. In the Fischer–Tropsch synthesis reaction, the incorporation of Ce markedly improved the activity and selectivity to C5+ hydrocarbons. Characterizations of the catalysts after Fischer–Tropsch synthesis confirmed the function of Ce as a chemical promoter. We also confirmed that the catalytic activity is associated with the concentrations of the surface polymeric and, to a lesser extent, atomic carbonaceous species and the C5+ selectivity correlated well with the surface concentration of Hägg carbide. We identified a linear relationship between the concentrations of the CeIII cations and Hägg carbide, which clearly substantiated the hypothesis that the chemical effect of Ce is mediated by the Fe0CeIII ensembles facilitating the formation of Hägg carbide.

show abstract

Effect of A12O3 Binder on the Precipitated Iron-Based Catalysts for Fischer-Tropsch Synthesis

Cited by 32 publications

References 26 publications

Promoting Role of Fe in the Preferential Oxidation of CO Over Ir/Al2O3

Promoting Role of Fe in the Preferential Oxidation of CO Over Ir/Al2O3

The Effect of Copper Loading on Iron Carbide Formation and Surface Species in Iron‐Based Fischer–Tropsch Synthesis Catalysts

Fischer–Tropsch Synthesis Over Skeletal FeCe Catalysts Leached from Rapidly Quenched Ternary FeCeAl Alloys

Contact Info

Product

Resources

About