Appendix A



Appendix A. Supplementary Material

Catalytic removal of toluene over three-dimensionally ordered macroporous Eu1(xSrxFeO3

Kemeng Ji, Hongxing Dai *, Jiguang Deng, Haiyan Jiang, Lei Zhang, Han Zhang, Yijia Cao

Laboratory of Catalysis Chemistry and Nanoscience, Department of Chemistry and Chemical Engineering, College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124, PR China.

* Corresponding author. Tel. No.: +8610-6739-6118; fax: +8610-6739-1983.

E-mail address: hxdai@bjut. (Prof. H.X. Dai)

Content

|Item |Page |

|Catalyst characterization procedures |3 |

|Fig. S1 |5 |

|TGA/DSC results |6 |

|Fig. S2 |8 |

|FT-IR results |9 |

|Fig. S3 |11 |

|C 1s XPS results |12 |

|Fig. S4 |13 |

Catalyst characterization procedures:

The X-ray diffraction (XRD) patterns were collected on a X-ray diffractometer (Bruker D8 Advance) using Cu Kα radiation and nickel filter (λ = 0.15406 nm), and the operating voltage and current were 40 kV and 35 mA, respectively. The JCPDS Database was used to identify the crystal phases of the samples. Thermogravimetric analysis (TGA) and differential scanning calorimetric (DSC) analysis were conducted in an air flow of 100 mL/min at a ramp of 15 oC/min from RT to 900 oC on a Seiko 6300 TG/DTA apparatus. Fourier transform infrared (FT-IR) spectra in the range of 400–4000 cm(1 with a resolution of 0.1 cm(1 of the samples (1 wt% sample + 99 wt% KBr) were recorded on a Bruker Vertex 70 spectrometer. The scanning electron microscopic (SEM) images of the samples were obtained on a Gemini Zeiss Supra 55 instrument operating at 10 kV. The transmission electron microscopic images (TEM) and selected-area electron diffraction (SAED) patterns of the samples were recorded on a JEOL-2010 equipment (operated at 200 kV). The nitrogen adsorption–desorption isotherms were measured at −196 oC on a Micromeritics ASAP 2020 analyzer with the samples being outgassed at 250 oC for 2 h. The specific surface areas of the samples were measured by the Brunauer-Emmett-Teller (BET) method, and the pore size distributions were calculated according to the Barrett-Joyner-Halenda (BJH) method. X-ray photoelectron spectroscopy (XPS, VG CLAM 4 MCD analyzer, resolution = 0.5 eV) was employed to determine the Eu 3d, Sr 3d, Fe 2p, O 1s, and C 1s binding energies (BEs) of surface species with Mg Kα (hν = 1253.6 eV) as the excitation source. Before each XPS analysis, the sample was pretreated in an O2 flow of 20 mL/min at 600 oC for 1 h and then cooled in the same atmosphere to RT. After being mounted and transferred into the spectrometer chamber in a transparent GLOVE BAG (Instruments for Research and Industry, USA) filled with helium to avoid exposure to air, the sample was outgassed in the preparation chamber (10−5 Torr) for 0.5 h and then introduced into the analysis chamber (3 ( 10−9 Torr) for recording. All of the obtained BE values were calibrated against the C 1s signal at BE = 284.6 eV of the contaminant carbon.

Hydrogen temperature-programmed reduction (H2-TPR) profiles of the samples were recorded on a Micromeritics Auto Chem II 2920 apparatus. Before each run, ca. 30 mg of the sample (40–60 mesh) was first placed in a quartz fixed-bed U-shaped microreactor (i.d. = 4 mm), and then pretreated in an O2 flow (30 mL/min) at 500 oC for 1 h. After cooled to RT in the O2 atmosphere, the sample was heated to 900 oC at a ramp of 10 oC/min in a 5% H2–95 % Ar (v/v) flow of 50 mL/min, and the outlet gases were measured on-line using a thermal conductivity detector (TCD). The thermal conductivity response was calibrated against the reduction of a known CuO powder sample (Aldrich, 99.995%).

Fig. S1. TGA/DSC profiles of the (A) EFO-3DOM and (B) EFSO-3DOM samples before calcination.

TGA/DSC results:

Fig. S1 illustrates the TGA and DSC profiles of the uncalcined EFO-3DOM and ESFO-3DOM samples. In case of the uncalcined EFO sample (Fig. S1A), there were three main weight losses of ca. 6, 44, and 48 wt% in the temperature ranges of RT(255, 255(341, and 341(423 oC, respectively, accompanied by the appearance of the corresponding three endothermic peaks centered at 149, 317, and 381 oC. The first weight loss could be attributed to the removal of adsorbed water and alcohol [1], and the reaction of citric acid (or EG) with metal nitrates to produce metal citrates [2] or glyoxylates ([C2H2O4]2−) [3]) and NOx [1]. The latter two weight losses were associated with the oxidative decomposition of the formed metal citrates or glyoxylates and the PMMA template [4]. As for the uncalcined ESFO sample (Fig. S1B), five weight losses of ca. 7, 10, 38, 35, and 3 wt% appeared, together with endothermic peaks centered at 128, 183, 209, 386, and 600 oC, respectively; the first four weight losses were similar to the case of the uncalcined EFO sample below ca. 450 oC, the fifth small and broad weight loss was due to the removal of oxycarbonate intermediates or residual carbonates [5]. The TGA/DSC results reveal that calcining the EFO and ESFO sample precursors at 750 oC was appropriate for the generation of a single-phase perovskite-type oxide structure, which has been confirmed by the FT-IR investigations (Fig. S2).

References:

[1] M. Sadakane, C. Takahashi, N. Kato, H. Ogihara, Y. Nodasaka, Y. Doi, Y. Hinatsu, W. Ueda, Three-dimensionally ordered macroporous (3DOM) materials of spinel-type mixed iron oxides. Synthesis, structural characterization, and formation mechanism of inverse opals with a skeleton structure, Bull. Chem. Soc. Jpn. 80 (2007) 677–685.

[2] M. Sadakane, R. Kato, T. Murayama, W. Ueda, Preparation and formation mechanism of three-dimensionally ordered macroporous (3DOM) MgO, MgSO4, CaCO3, and SrCO3, and photonic stop band properties of 3DOM CaCO3, J. Solid State Chem. 184 (2011) 2299–2305.

[3] M. Sadakane, T. Horiuchi, N. Kato, C. Takahashi, W. Ueda, Facile preparation of three-dimensionally ordered macroporous alumina, iron oxide, chromium oxide, manganese oxide, and their mixed-metal oxides with high porosity, Chem. Mater. 19 (2007) 5779–5785.

[4] H.W. Yan, C.F. Blanford, J.C. Lytle, C.B. Carter, W.H. Smyrl, A. Stein, Influence of processing conditions on structures of 3D ordered macroporous metals prepared by colloidal crystal templating, Chem. Mater. 13 (2001) 4314–4321.

[5] C.R. Gong, C.L. Song, Y.Q. Pei, G. Lv, G.L. Fan, Synthesis of La0.9K0.1CoO3 fibers and the catalytic properties for diesel soot removal, Ind. Eng. Chem. Res. 47 (2008) 4374–4378.

Fig. S2. FT-IR spectra of (a) EFO-bulk, (b) EFO-3DOM, and (c) EFSO-3DOM.

FT-IR results:

Fig. S2 shows the FT-IR spectra of the samples. The absorption bands at ca. 563, 586, and 633 cm(1 in the three samples were due to the Fe(O asymmetrical stretching vibration (ν1 mode), even though the absorption band corresponding to the O(Fe(O deformation vibration (ν2 mode) was not detected at around 430 cm(1 [1]. The red-shift at this location suggests the variation in coordinated environment of the iron ions. Besides, a shoulder peak at 628 cm(1 only observed in Fig. S2a indicates the formation of perovskite structure of the bulk EFO sample with lower symmetry, in good agreement with the orthorhombic structure revealed by the XRD studies [2,3]. Traces of carbonates, hardly observed from the XRD and TG results, were detected in the ESFO sample. The two absorption bands at ca. 864 and 1481 cm(1 should be assigned to the symmetrical stretching vibrations (ν2 and ν3 modes) of the CO32( ions [1,4]. No other absorption bands assignable to the organics were detected, indicating that calcining the sample precursors at 750 oC could totally remove all of the organics.

References:

[1] G.V.S. Rao, C.N.R. Rao, J.R. Ferraro, Infrared and electronic spectra of rare earth perovskites: Ortho-chromites, -manganites and -ferrites, Appl. Spectrosc. 24 (1970) 436–445.

[2] N. Escalona, S. Fuentealba, G. Pecchi, Fischer–Tropsch synthesis over LaFe1−xCoxO3 perovskites from a simulated biosyngas feed, Appl. Catal. A 381 (2010) 253–260.

[3] Y.C. Wei, J. Liu, Z. Zhao, Y.S. Chen, C.M. Xu, A.J. Duan, G.Y. Jiang, H. He, Highly active catalysts of gold nanoparticles supported on three-dimensionally ordered macroporous LaFeO3 for soot oxidation, Angew. Chem. Int. Ed. 50 (2011) 2326–2329.

[4] N.A. Merino, B.P. Barbero, P. Grange, L.E. Cadús, La1(xCaxCoO3 perovskite-type oxides: preparation, characterisation, stability, and catalytic potentiality for the total oxidation of propane, J. Catal. 231 (2005) 232–244.

Fig. S3. C 1s XPS spectra of (a) EFO-bulk, (b) EFO-3DOM, and (c) ESFO-3DOM.

C 1s XPS results:

Fig. S3 shows the C 1s XPS spectra of the three samples. One can clearly observe that there was a similar symmetrical C 1s XPS signal at ca. 284.6 eV for each sample, which generally came from the contaminated carbon. However, another rather weak C 1s signal at BE = ca. 288.9 eV appeared in each of the three samples, which was due to the surface carbonate species [1,2]. Such an observation was in good line with the FT-IR results. Therefore, no significant amounts of carbonate species were formed on the surface of the three samples.

References:

[1] H. Falcón, J. A. Barbero, J. A. Alonso, M. J. Martínez-Lope, J. L. G. Fierro, SrFeO3(δ perovskite oxides: chemical features and performance for methane combustion, Chem. Mater. 14 (2002) 2325(2333.

[2] J.L.G. Fierro, Structure and composition of perovskite surface in relation and catalytic properties, Catal. Today 8 (1990) 153(174.

Fig. S4. Toluene conversion and turnover frequency (TOF) as a function of reaction temperature over the EFO-bulk, EFO-3DOM, and EFSO-3DOM catalysts under the conditions of toluene concentration = 1000 ppm, toluene/oxygen molar ratio = 1/400, and SV = 20,000 mL/(g h).

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