Conversion of methane and n-pentane over Pt-Sn/γ-Al2O3 systems under non-oxidative conditions

• Published in: Russian chemical bulletin Vol. 69; no. 9; pp. 1703 - 1708
• Main Authors: Kazakova, O. A., Vinichenko, N. V., Golinskii, D. V., Belyi, A. S.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.09.2020; Springer Nature B.V
• Subjects: Additives; Aluminum oxide; Aromatic hydrocarbons; Benzene; Bimetals; Catalysts; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Dehydrogenation; Full Articles; Inorganic Chemistry; Lewis acid; Methane; Organic Chemistry; Platinum; Tin; Toluene; Transitional aluminas; methane; tin; non-oxidative conversion; platinum; aromatic hydrocarbons; hydrocarbon particles
• ISSN: 1066-5285; 1573-9171
• DOI: 10.1007/s11172-020-2951-z

Monometallic catalysts Pt/Al 2 O 3 and Sn/Al 2 O 3 and bimetallic systems Pt—Sn/Al 2 O 3 with the platinum and tin contents ∼0.51 and 0.13–0.38 wt.%, respectively, were synthesized. The introduction of tin into the Pt/Al 2 O 3 catalyst decreases the electron deficiency and dispersion of platinum but exerts almost no effect on the concentration of the Lewis acid sites on the support surface. The degree of dehydrogenation of the activated forms of methane (CH x fragments) on the catalysts with tin additives is lower than that on the surface of the monometallic Pt/Al 2 O 3 catalyst. The reactivity of the CH x species formed on the surface of the Pt—Sn/Al 2 O 3 samples was studied in the co-conversion of the activated forms of CH 4 with n-pentane to benzene and toluene under the non-oxidative conditions. The introduction of tin into the Pt/Al 2 O 3 decreases the electron deficiency of platinum but does not decrease the yield of aromatic hydrocarbons. The modifying effect of tin appears as a decrease in the degree of dehydrogenation of the activated forms of methane, which results in an increase in the reactivity of activated methane during co-conversion with n -pentane.