CNT catalyzed syngas conversion to lower olefins

Journal Pre-proof Crucial roles of support modification and promoter introduction in Fe/CNT catalyzed syngas conversion to lower olefins Yuan Fang, Junbo Cao, Xinxin Zhang (Investigation), Yueqiang Cao, Nan Song, Gang Qian, Xinggui Zhou, Xuezhi Duan (Conceptualization) (Methodology)

PII:

S0920-5861(20)30079-1

DOI:

https://doi.org/10.1016/j.cattod.2020.02.024

Reference:

CATTOD 12692

To appear in:

Catalysis Today

Received Date:

12 October 2019

Revised Date:

16 January 2020

Accepted Date:

19 February 2020

Please cite this article as: Fang Y, Cao J, Zhang X, Cao Y, Song N, Qian G, Zhou X, Duan X, Crucial roles of support modification and promoter introduction in Fe/CNT catalyzed syngas conversion to lower olefins, Catalysis Today (2020), doi: https://doi.org/10.1016/j.cattod.2020.02.024

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Crucial roles of support modification and promoter introduction in Fe/CNT catalyzed syngas conversion to lower olefins Yuan Fang#, Junbo Cao#, Xinxin Zhang, Yueqiang Cao*, Nan Song, Gang Qian, Xinggui Zhou, Xuezhi Duan* State Key Laboratory of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China *

Corresponding authors: [email protected]; [email protected]

#

The authors contributed equally to this work.

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Tel.: +86-21-64250937; Fax.: +86-21-64253528

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Highlights:

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Graphical Abstract:

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 Defect-rich CNT is appropriate for supporting Fe Fischer-Tropsch catalyst.  Relatively high K loading yields high FTO performance except catalyst stability.  The Mn against K is a promising promoter for enhanced FTO performance.

ABSTRACT: Producing lower olefins via iron-based Fischer-Tropsch synthesis without intermediate process has received increasing interests. Herein, effects of support modification on FTO performance of CNT supported Fe catalysts are comparatively investigated. Employing the defect-rich CNT as the catalyst support compared to the pristine CNT support is found to exhibit the shorter induction period and higher iron time yield (FTY). The promotional effects of K and Mn promoters on the FTO performance are subsequently revealed on the defect-rich CNT supported Fe catalysts. Both promoters are observed to suppress the

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formation of undesirable methane and to enhance the selectivity to desirable lower olefins. Moreover, the introduction of the Mn promoter facilitates the dispersion of iron particles and thus shows higher FTY, and it also gives rise to much higher catalyst stability than the K

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promoter. The insights reported here could guide the design and optimization of promoted Fe/C FTO catalysts.

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Keywords: Fe Fischer-Tropsch catalyst; lower olefins; carbon nanotubes; support

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modification; promoter effects

1. Introduction Iron-based Fischer-Tropsch-to-Olefins (FTO) process without intermediate steps has attracted a renewed and burgeoning interest for sustainable and short-flow production of lower olefins (i.e., C2=-C4=) [1-3]. In addition to the lower cost, higher availability and higher resistance to contaminants, the iron-based catalysts compared to other Fischer-Tropsch catalysts can directly convert coal- and -biomass-derived, CO-rich syngas without preadjustment of H2/CO to produce the targeted lower olefins [3-7,10]. Moreover, compared to

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cobalt-based FTO process, the iron-based FTO process is usually carried out at the relatively high temperature to shift the selectivity to short-chain hydrocarbons, and thus exhibits higher selectivity to lower olefins but lower selectivity to undesirable CH4 [2-4,8,9,29].

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Although the catalytic mechanism of the FTO process is very similar to that of traditional Fischer-Tropsch synthesis, the iron-based Fischer-Tropsch catalysts need to be properly

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modified for obtaining higher selectivity to lower olefins [3,4,6,7,11-14,30]. There are two

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consensuses that the weak metal-support interaction is favorable for the carburization of iron species and thus the formation of more active phase [1,2,6,7], and the introduction of

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appropriate promoters is beneficial for the desorption of lower olefins [3,4,15,16]. Previous studies have shown that nanostructured carbon materials and α-Al2O3 are appropriate for the

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iron-based FTO catalysts due to the endowed weak metal-support interaction [1-3], and the former one attracts more interests owing to the excellent properties including the higher surface

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area and electrical conductivity as well as tunable surface chemistry and textural properties [17-20]. Potassium and magnesium promoters have been widely used to promote the production of lower olefins [21-28]. Therefore, it is highly desirable to understand carbon supported iron catalysts and subsequent effects of promoters introduction for guiding design of carbon supported Fe-based FTO catalysts. In this work, the promotional effects of support modification were first demonstrated by

comparatively investigating pristine carbon nanotubes (CNT) and defect-rich CNT supported iron catalysts for FTO process. It was revealed that the defect-rich CNT support can promote the iron carburization process, and thus enhance the catalytic activity. Subsequently, two kinds of typical promoters, i.e., potassium and manganese, were introduced to iron catalysts supported on the defect-rich CNT to tailor the FTO performance. Finally, a plausible relationship of the catalyst structure and the FTO performance was established and discussed.

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2. Experimental section 2.1. Catalyst preparation

The commercial CNT from Beijing C-nano Technology Limited Company was modified in

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a mixed acid solution of 8 M H2SO4 and 8 M HNO3 [31,32,47]. 0.5 g of CNT was mixed with 200 mL acid solution by mechanically stirring and placed in ultrasound system for 2 h at 60 oC.

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After that, the mixture was filtered and washed by deionized water to neutral pH. Then, the

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samples were dried at 120 oC for 12 h. The oxidized sample was further calcined under a nitrogen flow at 800 oC for 2 h to introduce the defects on CNTs. The processed CNT was

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denoted as CNT-D.

The Fe/CNT and Fe/CNT-D catalysts were prepared by an incipient wetness impregnation

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method. A certain amount of Fe precursor, i.e., ammonium ferric citrate, was impregnated onto CNT and CNT-D, respectively, where the nominal loading of iron was kept as 10 wt%. The

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FeKx/CNT-D and FeMnx/CNT-D catalysts were also prepared by the same method. Potassium nitrate (AR, Adamas Reagent Co., Ltd.) and aqueous manganese nitrate (50 wt%, Adamas Reagent Co., Ltd.) were added to the precursor solution, respectively. The as-obtained samples were statically aged in the air at room temperature for 12 h and then dried in an oven at 120 oC for 12 h. Finally, the obtained catalysts were calcined at 500 oC under nitrogen for 2 h.

2.2. Catalyst characterization Transmission electron microscopy (TEM) was used to characterize the support and catalyst morphology and to measure the catalyst particle size over JEM-2100 operated at 120 kV. The surface chemistry properties of the samples were determined by Raman spectroscopy using LabRAM HR made by HORIBA Jobin Yvon. The qualitative analysis of the crystal phase of the supports, reduced and used catalysts was performed by X-ray diffraction (XRD) over RigakuD/Max2550VB/PC with Cu Kα radiation (λ = 1.54056 Å). The reducibility of the

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samples was determined by H2 temperature programmed reduction (H2-TPR) using AutoChem II 2920 made by Micromeritics.

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2.3. Catalytic testing

The performance of the catalyst was tested in a fixed-bed reactor. Typically, 100 mg of the

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catalyst was loaded in the reaction tube. The catalyst was reduced under H2 flow at 350 oC for

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12 h. After reduction, the reactor was cooled down to 300 oC under Ar flow, and the pressure was increased to the reaction pressure (i.e., 10 bar). The syngas (H2/CO=1) with a specific GHSV (15000 mL·h-1·gcat-1) was switched to the reactor. The outlet gas mixture of the reactor

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was detected by on-line gas chromatograph made by Echrom from China. Hydrocarbon components were detected by FID detector with the PLOT Q capillary column for separation

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and H2, CO, CO2 were detected by TCD detector with TDX-01 packed column for separation.

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External standard method was employed to analyze the reactants and products. Typically, the standard gas with known composition was injected to the GC, and then the areas of the peaks corresponding to different components were employed to divide the mole fraction of the components to yield the ratios for the components, i.e., CO, CO2, H2 and hydrocarbon products. During the reaction process, the reactants and products were determined by the online GC, and the determined the areas of the peaks assigned to CO, CO2, H2 and hydrocarbon products were

multiplied by the corresponding ratios obtained from the standard gas to yield the mole fraction of these components. The CO conversion was calculated by: CO Conversion (%)=

nin ∙yCO, in -nout ∙yCO,out nin ∙yCO, in

×100%

where nin and nout represent the reactor inlet gas molar flow rate and the outlet gas molar flow rate, respectively; yCO,in and yCO,out represent the CO molar percentage of inlet gas and the outlet

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gas, respectively.

The hydrocarbon selectivity (removal of by-product CO2) was calculated by: Mole of Cx hydrocarbon×x ×100% nin ∙yCO, in -nout ∙yCO,out -nout ∙yCO ,out

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Cx Hy Selectivity (%C)=

2

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where %C represents the percentage of the number of carbon atoms among the total number of

3. Results and discussion

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the carbon atoms in products.

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3.1. Crucial role of CNT modification

Pristine CNT was modified by mixed acid oxidation followed by high temperature treatment

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to introduce more defects onto the support surfaces. TEM measurements of the two supports

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in Fig. 1a and 1b show that the surfaces of the pristine CNT are relatively smooth, while those of the CNT-D are very rough. Further combining our previous studies [31,32], the above treatments could destroy the smooth CNT wall to introduce more defects onto the support surfaces. Along this line, Raman measurements of these two supports were performed, and the results are shown in Fig. 1c. The Raman spectra were deconvoluted into one Gaussian-shape peak located at 1500 cm-1 (i.e., D3) and four Lorentz-shape peaks located at 1200, 1350, 1580

and 1620 cm-1, which are denoted as D4, D1, G and D2, respectively [33]. The D1 and G are assigned to the A1g-symmetry vibration of the disordered graphitic lattice and E2g-symmetry vibration of the ideal graphitic lattice, respectively [34]. The intensity ratio of D1 to G (i.e., ID1/IG) is widely suggested to estimate the disorder degree or the defects amount of CNT. As expected, the calculated ID1/IG of the CNT-D is much higher than that of the pristine CNT. This

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is in good accordance with the rough surfaces of the CNT-D in the TEM image.

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Fig. 1. Representative TEM images of CNT (a) and CNT-D (b). (c) Raman spectra of the two supports. (d) XRD patterns of the reduced Fe/CNT and Fe/CNT-D catalysts, where standard

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pattern of Fe3O4 (JCPDS No. 03-0863) is also presented for comparison.

The two resultant carbon supports were then employed to immobilize Fe catalysts for

probing the effects of the support modification. XRD measurements of the reduced Fe/CNT and Fe/CNT-D catalysts in Fig. 1d both show characteristic diffraction peaks of Fe3O4 in addition to those of carbon, indicating that the support modification shows negligible change

in the iron crystal phase. Fig. 2a exhibits CO conversion as a function of time on stream over Fe/CNT and Fe/CNT-D catalysts. Both catalysts show the increased CO conversion with the time on stream in the initial reaction period. This period is normally called as the induction period, which is associated with the formation of active iron carbides phase [30]. The duration of the induction period seen with the Fe/CNT-D is about 14 h, shorter than that of the Fe/CNT (i.e., 21 h), indicating that the induction process is remarkably promoted by the CNT modification. Furthermore, the initial activity of the Fe/CNT-D catalyst is obviously higher that

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of the Fe/CNT catalyst, agreeing well with the shorter induction period observed with the Fe/CNT-D catalyst. These differences could be resultant from different formation processes of

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active phase for the FTO process, i.e., the active iron carbides, which will be discussed below.

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Fig. 2. (a) CO conversion as a function of time on stream over Fe/CNT and Fe/CNT-D catalysts.

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(b) H2-TPR profiles obtained for the calcined Fe/CNT and Fe/CNT-D catalysts. Representative TEM images of Fe/CNT (c) and Fe/CNT-D (d) catalysts. The insets are the corresponding

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histograms of the particle size distributions. (e) Comparison of the FTY for Fe/CNT and Fe/CNT-D catalysts. (d) XRD patterns of Fe/CNT and Fe/CNT-D catalysts. Standard patterns of Fe3O4 (JCPDS No. 03-0863) and Fe5C2 (JCPDS No. 36-1248) are also presented for comparison.

Previous studies have shown that the reducibility of the iron species on the support and the

Fe particle size have strong influences on the induction periods and thus the formation of active iron carbides [2,30,35]. The H2-TPR measurements were first carried out for the calcined Fe/CNT and Fe/CNT-D samples to investigate the effects of the CNT modification on the reducibility of the iron species. As seen in Fig. 2b, the TPR profile of Fe/CNT shows three peaks at the temperature of 281, 319 and 404 oC, which are assigned to the reduction of Fe2O3 to Fe3O4 and the further reduction of Fe3O4 to FeO as well as the reduction of FeO to Fe0, respectively [11,36-38]. The peak observed at the temperature higher than 600 oC is assigned

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to the gasification of carbon support in H2 at high temperature [11,42,44]. For the Fe/CNT-D, all the reduction peaks of the iron species shift to lower temperature, suggesting the more facile reduction of iron species over the Fe/CNT-D catalyst, which might promote the iron

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carbonization process for the formation of active iron carbides phase.

Besides, the CNT modification could also change the Fe particle size and thus influence the

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induction process. TEM characterizations were performed for the catalysts to explore the

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effects of the CNT modification on the Fe particle size, and the results are shown in Fig. 2c and 2d. It can be observed that the Fe nanoparticles are dispersed on the CNT and CNT-D with the similar average diameters and particle size distributions. In other words, the CNT

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modification shows negligible effects on the particle size. Therefore, the shortened time of the induction period of the Fe/CNT-D catalyst, i.e. the promoted induction process, should be

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mainly attributed to the facilitated reduction process of iron species on the Fe/CNT-D catalyst.

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As also seen in Fig. 2a, the CO conversion over the Fe/CNT-D catalyst is around 70%, while that over the Fe/CNT catalyst is only around 50%. The calculated FTY of the Fe/CNT and Fe/CNT-D catalysts are further compared in Fig. 2e, in which the FTY of the Fe/CNT-D catalyst is obviously higher than that of the Fe/CNT catalyst. These results indicate that the CNT modification not only promotes the induction process, but also increases the FTO activity, which could be associated with the more active sites. XRD measurements of the two catalysts

in Fig. 2f show a shoulder peak at right side of the C(100) diffraction peak over the Fe/CNT-D catalyst, which is most likely assigned to the diffraction peak of -Fe5C2 (510). In contrast, this shoulder peak is hardly seen with the XRD pattern of the Fe/CNT catalyst, which suggests that the amount of formed -Fe5C2 phase over the Fe/CNT catalyst is much less than that over the Fe/CNT-D catalyst. Previous theoretical and experimental studies have shown that the dominant active phase for iron-based FTO process is the -Fe5C2 phase [1,29,39-41]. Therefore, it could be concluded that the promoted induction process by the CNT modification favors the

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formation of -Fe5C2 phase over the Fe/CNT-D catalyst and thus enhances the catalytic activity.

3.2. Remarkable promoter effects

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The above results shown in Section 3.1 shows promotional effects of the carbon support modification. As a consecutive effort, the effects of promoters on the FTO performance were

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further explored by introducing K or Mn promoter to iron catalysts supported on the CNT-D

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via a co-impregnation method. As shown in Table 1, the increase in the K promoter from 0.5 to 1.5% shows similar CO conversions but remarkably different FTO performance. Compared

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to the Fe/CNT-D catalyst, the promoted Fe/CNT-D catalysts with lower K contents (i.e., FeK0.5/CNT-D and FeK1.0/CNT-D) exhibit lower selectivity to C2-C4 olefins at similar CO

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conversions. Moreover, these two promoted catalysts show decreased hydrocarbon selectivity (i.e., CH selectivity), which might be ascribed to the facilitated water-gas shift (WGS) reaction

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and thus increased selectivity to CO2. However, the increased WGS activity and thus higher H2/CO ratio favorable for hydrogenation processes don’t lead to higher selectivities to C2-C40 and CH4 in comparison to the unpromoted catalyst. This is most likely attributed to the weakened activation of hydrogen by the K promoter [45], which can suppress the undesirable methanation as well as the olefins over-hydrogenation and thus higher O/P ratios.

Table 1. FTO performances of Fe/CNT-D and promoted Fe/CNT-D catalysts. Fe/ CNT-D

FeK0.5/ CNT-D

FeK1.0/ CNT-D

FeK1.5/ CNT-D

FeMn5/ CNT-D

FeMn10/ CNT-D

CO conversion

39.49%

37.86%

36.54%

37.35%

42.35%

31.18%

CH selectivity* (%C)

68.53%

50.00%

41.18%

40.78%

57.88%

53.62%

CH4

27.85%

10.43%

9.54%

16.39%

10.83%

12.38%

C2-C4=

34.81%

22.99%

25.39%

41.55%

32.13%

42.81%

C2-C40

12.66%

3.80%

3.65%

6.14%

4.73%

6.57%

C5+

24.68%

62.78%

61.42%

35.92%

52.31%

39.24%

O/P ratio+

2.75

6.04

6.96

6.77

6.80

6.51

148.39

128.21

129.78

208.86

142.46

FTY (µmolCO·gFe-1·s-1) 230.59 * The

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Catalysts

hydrocarbon selectivities are normalized, with the exception of CO2. + The olefin (i.e., O) and paraffin

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(i.e., P) are C2-C4= and C2-C40, respectively. Reaction condition: 10 bar, 300 oC, H2/CO = 1, GHSV =

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15000 mL·h-1·gcat-1.

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Moreover, the K-promoted Fe/CNT-D catalysts show higher C5+ selectivity than the Fe/CNT-D catalyst, agreeing well with previous studies that the suppressed H2 activation can

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increase the chain growth probability and thus the selectivity to long-chain hydrocarbons [40,46,47]. However, further increasing the K content to 1.5% (i.e., FeK1.5/CNT-D) would

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result in higher selectivity to CH4, which is out of the trend seen with the FeK0.5/CNT-D and FeK1.0/CNT-D catalysts. This might be mainly due to the higher H2/CO ratio for the

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FeK1.5/CNT-D catalyst than those for the FeK0.5/CNT-D and FeK1.0/CNT-D catalysts by the further promoted WGS reaction, as revealed by the lower hydrocarbon selectivity of FeK1.5/CNT-D. Furthermore, the higher H2/CO ratios largely suppressed the chain growth over the FeK1.5/CNT-D catalyst and thus the lower C5+ selectivity, while promoted the formation of C2-C4 hydrocarbons, which simultaneously increased the selectivities of lower olefins and paraffins.

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Fig. 3. (a) CO conversion as a function of time on stream over the unpromoted and K- and Mnpromoted Fe/CNT-D catalysts. Representative TEM images of the K-promoted Fe/CNT-D

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catalysts: (b) FeK0.5/CNT-D, (c) FeK1.0/CNT-D, (d) FeK1.5/CNT-D, (e) FeMn5/CNT-D and (f)

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FeMn10/CNT-D catalysts. The corresponding average Fe particle sizes over the K- and Mn-

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promoted catalysts. The histograms of the particle size distributions are shown in Fig. S2.

Interestingly, the Mn-promoted catalysts show higher CH selectivity and FTY than the K-

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promoted ones at similar CO conversions, suggesting that the Mn is a promising candidate to act as the promoter of Fe-based FTS catalyst. Notably, the higher Mn loading over the

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FeMn10/CNT-D catalyst shows lower CO conversion and CH selectivity but higher CH4 selectivity and O/P ratio as well as lower C5+ selectivity, which is most likely due to the suppressed CO activation and increased hydrogenation activity by the Mn promoter [48]. Moreover, the results of CO conversion as a function of time on stream in Fig. 3a show that the FeK1.5/CNT-D catalyst shows similar initial CO conversion compared to the Fe/CNT-D catalyst, while the other two K-promoted catalysts with the lower K loadings exhibits lower

initial CO conversions. These phenomena could be rationally interpreted by the results of TEM characterization in Fig. 3b-3d that the FeK1.5/CNT-D catalyst shows slightly larger iron particle size and the Fe/CNT-D catalyst, while the other two K-promoted catalysts with much larger ones. This is in good agreement with previous results that decreasing the iron particle size gives rise to the increased apparent TOF [29]. It is also observed in Fig. 3 that the Mn-promoted catalysts show suppressed catalytic activity than the FeK1.5/CNT-D and unpromoted Fe/CNT-D catalysts, but the introduction of

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Mn promoter yields smaller iron particle sizes. This indicates that there exist other influencing factors for different catalytic behaviors for the promoter effects. In order to understand these issues, XRD characterization of different promoted catalysts against unpromoted one were

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carried out. As shown in Fig. 4a, the promoted catalysts especially for the K-promoted ones exhibit more characteristic diffraction peaks corresponding to the (510) plane of -Fe5C2 than

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the unpromoted one, which indicates more active phase in the K-promoted catalysts. The

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formed -Fe5C2 is also verified by the HRTEM image shown in Fig. S1, in which a d-spacing of 0.203 nm corresponding the lattice fringe of -Fe5C2 (510) facet is clearly observed.

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Considering that -Fe5C2 is the active phase for FTO process [30], the K-promoted Fe/CNT-D catalysts should exhibit higher activity but actually show lower activity than the unpromoted

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catalyst. This is most likely associated with the carbon deposition on the catalysts as also seen in Fig. S1. The K promoter induced carbon deposition could be unveiled in the future by using

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carbon-free support for the catalysts to avoid the relevant interferences from the support.

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Fig. 4. (a) XRD patterns and (b) H2-TPR profiles of the promoted and unpromoted Fe/CNT-D catalysts.

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In addition to the different initial catalytic activities of these catalysts, the Mn-promoted Fe/CNT-D catalysts show shorter induction period than the unpromoted Fe/CNT-D catalyst

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(Fig. 3a), which could be associated with the changed reduction process of the iron species by

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the promoter. As seen in Fig. 4b, the reduction peaks of iron species over the Mn-promoted CNT-D catalysts shift to the lower temperature compared to those of the Fe/CNT-D catalyst.

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These suggest that the reduction process is facilitated on the Mn-promoted catalysts, which is favorable for the further carburization process and thus the shorter induction period than the

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unpromoted Fe/CNT-D catalyst. In contrast, the reduction peaks of iron species over the Kpromoted Fe/CNT-D catalysts shift to higher temperature compared to those of the unpromoted

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Fe/CNT-D catalyst, indicating the unfavorable reduction process over K-promoted Fe/CNT-D catalysts, possibly due to the larger iron particle sizes in Fig. 3b-3d and/or the electronic effects caused by the potassium oxides [45]. However, the seemingly shorter induction periods observed with the K-promoted Fe/CNT-D catalysts in Fig. 3a, which is most likely overlapped with the catalysts deactivation mentioned above. Based on all the above analyses, the Mn promoter shows promising to be the candidate for

the promoter of Fe-based FTS catalysts. In contrast, for the way to introduce the K promoter into Fe-based catalysts in this work is not favorable for the FTO reaction. It should be noted that the methods to prepare Fe/C composites and to introduce K and/or Mn promoters play a vital role in the FTO performance, probably due to the resultant different location of iron species and the promoters over the catalysts [6,7,28,30,49]. Thus, further investigations on the effects of the local environment of the promoter and iron species should be carried out to design

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more efficient promoted Fe/C FTO catalysts.

4. Conclusions

In summary, we have revealed the effects of the support modification and promoter

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introduction of Fe/CNT catalysts on the FTO performance. The defect-rich CNT has been shown to be the good candidate support for immobilizing Fe catalysts because of the enhanced

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iron carburization process and catalytic activity. The relatively high loading of K promoter has

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been associated with the facilitated FTO process except the severe catalyst deactivation mainly caused by the carbon deposition. However, the promotional effects of the Mn promoter against

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the K promoter have been suggested as the promising promoter to achieve better FTO performance, i.e., the suppressed formation of CH4 and alkanes, the enhanced formation of C2-

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C4 olefins and the higher catalyst stability. These results could be helpful for understanding the FTO process over promoted Fe/C composite catalysts and thus guiding their rational design

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and manipulation.

Credit Author Statement: Yuan Fang: Catalyst Preparation and Characterization, Catalytic Testing, Paper Preparation. Junbo Cao: Data Processing, Paper Preparation. Xinxin Zhang: Investigation, Discussion.

Yueqiang Cao: Investigation, Methodology, Paper Preparation. Nan Song: Discussion. Gang Qian: Discussion. Xinggui Zhou: Discussion, Language Polish Xuezhi Duan: Conceptualization, Methodology, Paper Revision.

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Declaration of interests

☒ The authors declare that they have no known competing financial interests or personal

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relationships that could have appeared to influence the work reported in this paper.

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Acknowledgements

This work was financially supported by the Natural Science Foundation of China (21922803,

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21776077 and 91434117), the Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning, the Natural Science Foundation of Shanghai

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(17ZR1407300), the Shanghai Rising-Star Program (17QA1401200), the Fundamental Research Funds for the Central Universities (222201718003) and the Open Project of State

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Key Laboratory of Chemical Engineering (SKL-Che-15C03).

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