Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2019 Nov 24;12(23):3878.
doi: 10.3390/ma12233878.

Magnetic Fe3O4@SiO2-Pt and Fe3O4@SiO2-Pt@SiO2 Structures for HDN of Indole

Robinson Dinamarca  1   2 , Verónica Valles  3 , Brenda Ledesma  3 , Cristian H Campos  1 , Gina Pecchi  1   4 , Andrea Beltramone  3
Affiliations

Magnetic Fe3O4@SiO2-Pt and Fe3O4@SiO2-Pt@SiO2 Structures for HDN of Indole

Robinson Dinamarca et al. Materials (Basel). .

Abstract

The effect of a second porous SiO2 shell in the activity and selectivity of the Fe3O4@SiO2-Pt catalyst in the hydrodenitrogenation of indole is reported. The double Fe3O4@SiO2-Pt@SiO2 structure was prepared by coating Fe3O4 nanoparticles with tetraethyl orthosilicate (TEOS) with a further impregnation of 1.0 wt.% of Pt on the (3-aminopropyl)triethoxysilane functionalized Fe3O4@SiO2 structures. The second porous SiO2 shell, obtained by using a hexadecyltrimethylammonium bromide (CTAB) template, covered the Fe3O4@SiO2-Pt catalyst with a well-defined and narrow pore-sized distribution. The full characterization by TEM, inductively coupled plasma-optical emission spectroscopy (ICP-OES), XRD, and N2 adsorption isotherm at 77 K and vibrating sample magnetometry (VSM) of the catalysts indicates homogeneous core@shell structures with a controlled nano-size of metallic Pt. A significant effect of the double SiO2 shell in the catalytic performance was demonstrated by both a higher activity to eliminate the nitrogen atom of the indole molecule present in model liquid fuel and the improvement of the catalytic stability reaching four consecutive reaction cycles with only a slight conversion level decrease.

Keywords: core@shell; indole HDN; mesoporous materials; platinum.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
HR-TEM of the synthesized Fe3O4–NPs and core@shell structures. (a) Fe3O4; (b) Fe3O4@SiO2; (c) Fe3O4@SiO2-Pt; (d) Fe3O4@SiO2-Pt@mSiO2.
Figure 2
Figure 2
XRD of the synthesized Fe3O4–NPs and core@shell structures.
Figure 3
Figure 3
X-ray source spectrophotometry (XPS) of the Pt 4f7/2 of the Fe3O4@SiO2–Pt core@shell structure.
Figure 4
Figure 4
N2 adsorption isotherms and pore size distribution of the core@shell structures.
Figure 5
Figure 5
Vibrating sample magnetometer (VSM) of the synthesized Fe3O4–NPs and core@shell structures.
Scheme 1
Scheme 1
Reaction pathways for hydrodenitrogenation (HDN) of indole: indole (IND), indoline (HIN), o-ethylaniline (OEA), ethylbenzene (EB), octahydroindole (OHIN), o-ethylcyclohexylamine (OECHA), ethylcyclohexene (ECHE), and ethylcyclohexane (ECH).
Figure 6
Figure 6
Indole conversion over the synthesized catalysts.
Figure 7
Figure 7
Molar fraction of indole and products in HDN reaction (a) Fe3O4@SiO2–Pt; (b) Fe3O4@SiO2–Pt@mSiO2.
Figure 8
Figure 8
Reutilization study of the catalysts at 5 h of reaction time.
See this image and copyright information in PMC

References

    1. Egorova M., Prins R. Competitive hydrodesulfurization of 4,6-dimethyldibenzothiophene, hydrodenitrogenation of 2-methylpyridine, and hydrogenation of naphthalene over sulfided NiMo/γ-Al2O3. J. Catal. 2004;224:2782–2787. doi: 10.1016/j.jcat.2004.03.005. - DOI
    1. Egorova M., Prins R. Mutual influence of the HDS of dibenzothiophene and HDN of 2-methylpyridine. J. Catal. 2004;221:11–19. doi: 10.1016/S0021-9517(03)00264-1. - DOI
    1. Nassreddine S., Massin L., Aouine M., Geantet C., Piccolo L. Thiotolerant Ir/SiO2–Al2O3 bifunctional catalysts: Effect of metal—Acid site balance on tetralin hydroconversion. J. Catal. 2011;278:253–265. doi: 10.1016/j.jcat.2010.12.008. - DOI
    1. Kishore Kumar S.A., John M., Pai S.M., Niwate Y., Newalkar B.L. Low temperatura hydrogenation of aromaticsover Pt–Pd/SiO2–Al2O3 catalyst. Fuel Process. Technol. 2014;128:303–309. doi: 10.1016/j.fuproc.2014.07.028. - DOI
    1. Jongpatiwut S., Li Z., Resasco D.E., Alvarez W., Sughrue E., Dodwell G. Competitive hydrogenation of poly-aromatic hydrocarbons on sulfur-resistant bimetallic Pt-Pd catalysts. Appl. Catal. 2004;262:241–253. doi: 10.1016/j.apcata.2003.11.032. - DOI

LinkOut - more resources