Preparation of highly ordered Fe-SBA-15 by physical-vapor-infiltration and their application to liquid phase selective oxidation of styrene

• Published in: Journal of molecular catalysis. A, Chemical Vol. 268; no. 1; pp. 155 - 162
• Main Authors: Zhang, Ling-Xia, Hua, Zi-Le, Dong, Xiao-Ping, Li, Lei, Chen, Hang-Rong, Shi, Jian-Lin
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.05.2007; Elsevier
• Subjects: Catalysis; Chemistry; Colloidal state and disperse state; Exact sciences and technology; Ferric oxides; General and physical chemistry; Hydrogen peroxide; Mesoporous silica; Physical-vapor-infiltration; Porous materials; Selective oxidation; Styrene; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Ferric oxides; Selective oxidation; Hydrogen peroxide; Physical-vapor-infiltration; Mesoporous silica; Styrene; Vapor; Hydrocarbon; Oxides; Iron; Liquid phase; Porous material; Silica; Mesoporosity; Heterogeneous catalysis; Preparation; Benzenic compound; Infiltration; Oxidation
• ISSN: 1381-1169; 1873-314X
• DOI: 10.1016/j.molcata.2006.12.027

Highly ordered Fe-SBA-15 with an extraordinary high Fe loading amount up to 24 mol% has been prepared by a new simple physical-vapor-infiltration method and show a significantly high selectivity for benzaldehyde in liquid phase selective oxidation of styrene with hydrogen peroxide as the oxygen source. ▪ A simple physical-vapor-infiltration (PVI) method was applied to prepare highly ordered Fe-containing mesoporous silica SBA-15. The loading amount of Fe in SBA-15 was very high (up to 24 mol%) and can be tuned by using different PVI time. The liquid phase selective oxidation of styrene with H 2O 2 has been used to characterize their catalytic properties, the major product is benzaldehyde and the minor is styrene oxide. Independent of the Fe contents and the heat treatment temperature, the selectivity for benzaldehyde in the reaction at a mild temperature of 50 °C are all above 91%. At elevated temperature of 70 °C, the conversion rate of styrene increases beyond 36% and more significantly the selectivity for benzaldehyde can reach as high as 99%. Comparatively, another two different schemes (simple wet impregnation and incorporation using silane coupling agent) have been also applied to synthesize Fe-containing SBA-15 samples. Under the same condition, the styrene conversion on these two samples are both very low with minor product of phenylacetaldehyde and other styrene oxides.