Synergistic BAl interaction in SBA-15 affording an enhanced activity for the hydro-isomerization of heptane over PtBAl-SBA-15 catalysts

• Published in: Microporous and mesoporous materials Vol. 281; pp. 142 - 147
• Main Authors: Rizescu, C., Cojocaru, B., Thanh Hien, N.T., Huyen, P.T., Parvulescu, V.I.
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.06.2019
• Subjects: Hydro-isomerization of heptane; Pt-B[sbnd]Al-SBA-15 catalysts; Resistance against cocking; Selectivity to methylhexanes. cracking of heptane to C1[sbnd]C4 molecules; Hydro-isomerization of heptane; Resistance against cocking; Pt-BAl-SBA-15 catalysts; Selectivity to methylhexanes. cracking of heptane to C1C4 molecules
• ISSN: 1387-1811; 1873-3093
• DOI: 10.1016/j.micromeso.2019.03.020

Mesoporous M-SBA-15 (M/Si = 1/10) (where M = Al, B or AlB in a ratio 0.5:0.5) were prepared via a known procedure using poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) (P123) as template. Further deposition of platinum on these supports has been achieved by impregnation with an aqueous solution of H2PtCl6. The prepared supports and catalysts were characterized by the adsorption-desorption isotherms of nitrogen at −196 °C, XRD and TEM measurements, and temperature-programmed desorption of ammonia (TPD-NH3). All these solids were investigated for the hydro-isomerization of heptane. In the investigated range of time (24 h) and temperatures (200–300 °C) the supports exhibited no isomerization activity but only a small cracking activity. The addition of platinum to these supports provided activity in this reaction even for a weak acid support as B-SBA-15. However, the presence of both aluminum and boron in a ratio of 0.5 to 0.5 led to a more efficient catalyst. Thus, the PtAlB-SBA-15 catalyst showed a slightly higher conversion than the PtAl-SBA-15 one. All the investigated Pt-SBA-15 provided high selectivity for the isomerization to methylhexanes. Dimethylpentanes were also produced but in a different extent, depending on the acidity of the support. Cracking of heptane to C1C4 molecules accompanied the hydro-isomerization process but in a rather small extent (yields smaller than 5% after 24 h). [Display omitted] •Mesoporous M-SBA-15 (M/Si = 1/10) (where M = Al, B or AlB in a ratio 0.5:0.5) were utilized as supports for the Pt catalysts.•Pt/M-SBA-15 shown catalytic behaviour for the hydro-isomerization of heptane.•Methylhexanes are the main isomerization products.•Dimethylpentanes were also produced but in a smaller extent.