Please cite this article in press as: H. Pérez, et al., Evaluation of manganese OMS-like cryptomelane supported on SBA-15 in the oxidation of ethyl acetate, Catal. Today (2012), http://dx.doi.org/10.1016/j.cattod.2012.09.022 ARTICLE IN PRESS G Model CATTOD-8249; No. of Pages 8 Catalysis Today xxx (2012) xxx–xxx Contents lists available at SciVerse ScienceDirect Catalysis Today jou rn al h om epage: www.elsevier.com/locate/cattod Evaluation of manganese OMS-like cryptomelane supported on SBA-15 in the oxidation of ethyl acetate Hermicenda Pérez a,b , Paloma Navarro a,∗ , Gilberto Torres b , Oihane Sanz a , Mario Montes a a Department of Applied Chemistry, University of the Basque Country (UPV-EHU), Apdo. 1072, 20080 San Sebastián, Spain b Academic Division of Basic Science, Autonomous University Juárez of Tabasco, Km. 1, Road Cuanduacán-Jalpa de Méndez, A.P. 24, C.P. 86690, Cuanduacán, Tabasco, Mexico a r t i c l e i n f o Article history: Received 15 March 2012 Received in revised form 14 September 2012 Accepted 24 September 2012 Available online xxx Keywords: Catalytic VOC abatement Cryptomelane Manganese oxides Supported manganese catalysts SBA-15 a b s t r a c t We report the synthesis of four manganese catalysts supported on SBA-15 via a multistep impregnation method. The successive impregnations allowed as much as 13.8% manganese to be deposited without loss of the mesoporous structure of the SBA-15, although the surface area of the catalysts and their pore size distributions were lower than those of the pure SBA-15. The data obtained using different analysis techniques indicate that the manganese was incorporated into the pure SBA-15 in different positions: grafted onto the internal surface of the walls, incorporated into the framework of the SBA-15 and on the external surface and at the pores mouth of the SBA-15, which partially blocked the porosity. The XRD results showed that cryptomelane phase was formed in all of the catalysts; the remaining P123 in the SBA-15 structure and the presence of K + during the impregnation most likely favored the formation of the cryptomelane phase. Total oxidation of ethyl acetate in air was obtained at temperatures less than 350 ◦ C for all of the catalysts. © 2012 Elsevier B.V. All rights reserved. 1. Introduction Volatile organic compounds (VOCs) are major organic atmo- spheric pollutants. The emission of VOCs is being subjected to stricter legislation, and, although the prevention of emissions would be the most desirable strategy to control VOCs, such pre- vention is often not feasible; thus, the destruction of VOCs is an alternative. Incineration and catalytic oxidation are the most com- monly used techniques to treat VOC-contaminated streams. Simple incineration requires high temperatures (800–1150 ◦ C) and can produce incomplete oxidation products that are also dangerous. In contrast, catalytic oxidation can typically be achieved in the temperature range of 200–500 ◦ C depending on the nature of the molecule. Furthermore, this technique can be applied effectively at low cost to a wide concentration range of VOCs. Therefore, cat- alytic oxidation appears to be a good alternative for the complete elimination of VOCs. Noble metals like Pt or Pd supported on alumina or silica are widely used for VOC abatement. However, these catalysts are not only expensive, but are also susceptible to sintering and poison- ing. An additional difficulty in the treatment of VOCs arises from ∗ Corresponding author. Present address: Institute of Catalysis and Petroleochem- istry of the Spanish Council for Scientific Research (ICP-CSIC), Marie Curie Street 2, Cantoblanco, 28049 Madrid, Spain. Tel.: +34 91 585 4793. E-mail address: pnavarro@icp.csic.es (P. Navarro). the fact that streams generally contain a mixture of organic com- pounds of different chemical nature, and the catalyst must be able to oxidize them simultaneously. Therefore, because the activity of a catalyst largely depends on the nature of the molecule to be oxidized, the design of adequate catalysts for specific processes has been the focus of numerous investigations. Investigations that involve metal-oxide catalysts instead of the more commonly used noble-metal catalysts are becoming relevant, and such investiga- tions have focused on manganese because of its low cost and good performance in the oxidation of some VOCs [1,2]. For example, ethyl acetate has been reported to be more readily oxidized on MnO 2 than on Pt/Al 2 O 3 [3,4]. The synthesis of MnO x phases have been studied for a long time, and the literature shows that the nature of these MnO x catalysts depends strongly on the precursor used, the thermal treatment given and the support itself [5,6]. Nevertheless, the synthesis and characterization of these materials still attract considerable atten- tion from both academia and industry [7,8]. Catalytic supports should have a high surface area to improve dispersion of the active phase, which is why mesoporous molecular sieves (MMSs) have attracted so much interest since their discov- ery [9,10]. Mesoporous materials, such as MCM-41 and SBA-15, exhibit high surface areas (500–1000 m 2 /g) and a hexagonal array of uniform cylindrical mesopores with diameters that can be tailo- red from 5 nm to 30 nm. However, the purely siliceous MMS show limited catalytic applications because they lack acidity. Therefore, the incorporation of various metals into their frameworks has been 0920-5861/$ – see front matter © 2012 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.cattod.2012.09.022