Reactive H 2 S chemisorption on mesoporous silica molecular sieve-supported CuO or ZnO Diana Montes a , Edumaris Tocuyo a , Eduardo González a , Douglas Rodríguez a , Roger Solano a , Reinaldo Atencio b , Miguel A. Ramos b , Alexander Moronta a,⇑ a Instituto de Superficies y Catálisis, Facultad de Ingeniería, Universidad del Zulia, Maracaibo 4003, Venezuela b Instituto Zuliano de Investigaciones Tecnológicas (INZIT), km 14 vía La Cañada de Urdaneta, Estado Zulia, Venezuela article info Article history: Received 8 August 2012 Received in revised form 26 September 2012 Accepted 26 September 2012 Available online 4 October 2012 Keywords: H 2 S removal Mesoporous silica Metal oxide content abstract Natural gas, a valuable energy carrier, can be used as a fuel or as a raw material for the production of syn- thesis gas and hydrogen. However, significant quantities of undesirable contaminants, especially hydro- gen sulfide (H 2 S), generate harmful environmental emissions. The objective of this work was to develop a scavenger system for the H 2 S removal at room temperature. The potential of mesoporous silica molecular sieve (MSU-1) supported ZnO or CuO adsorbents has been studied at room temperature for H 2 S removal to develop a more effective adsorbent for this important application. Zn 2+ or Cu 2+ loadings of 10, 20 and 30 wt.% were incorporated by the incipient wetness method. The obtained solids were characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), temperature programmed reduction (TPR), scanning electron microscopy (SEM) and N 2 adsorption/desorption, using the BET method, to investigate their var- ious characteristics. The MSU-1 support did not show activity for H 2 S removal, however the addition of copper or zinc increased the removal performance. The most active solids for H 2 S were 10Zn/MSU-1 (42.3 mg g 1 ) and 20Cu/MSU-1 (19.2 mg g 1 ). A decrease in H 2 S removal was observed at a zinc loading higher than 10 wt.% (14.8 and 11.5 mg g 1 for 20 and 30Zn/MSU-1), while 10Cu/MSU-1 presented a low adsorption capacity (10.9 mg g 1 ) and 30Cu/MSU-1 has a similar performance than that of 20Cu/MSU-1. The adsorption capacity of the obtained materials strongly depends on the pore system as well as the well-proportioned distribution of the active phase inside the porous material and the size of metal oxide nanoparticles. Ó 2012 Elsevier Inc. All rights reserved. 1. Introduction Hydrogen sulfide and other compounds containing sulfur can be found in natural gas and other industrially important hydrocarbon feedstock [1,2]. Hydrogen sulfide (H 2 S) is considered as one of the most noxious industrial gases for the atmosphere [3,4]. Its removal from natural gas is particularly required for reasons of health (e.g., sore throats, breathing difficulties, respiratory infections), odor problems and safety; it also causes pipelines corrosion that limits plant lifetime [1] and might poison many industrial catalysts [5,6]. Many methods have been developed over years for removal of H 2 S from gaseous emissions. H 2 S removal, with subsequent sul- fur recovery, is at present mostly preferred using the Claus process [7]. Some of the disadvantages of this method for gas treatment are that it requires relatively large investment and operational costs (e.g., special chemicals, corrosion equipment, high pressures and temperatures) and they require special operational safety and health procedures. Due to chemical affinity of H 2 S for metallic cations, the most frequently used technique to purify natural gas from its hydrogen sulfide constituents is chemical reaction over a solid surface. The removal of H 2 S molecules from natural gas, to obtain low concen- trations, is mainly conducted utilizing solid adsorbents at high temperatures, ranging from 200 to 800 °C. Copper and zinc, with their superior properties, are classified as the most favorable met- als for the removal of H 2 S. The pure metal oxides used as sorbents, however, suffer from evaporation, loss in the surface area and porosity, sintering and mechanical disintegration that affect their performance and life time adversely. With the purpose of overcom- ing this problem and to improve their performance, metal oxides are loaded to the inert support materials with high surface area. In the literature it has been widely reported the use of metal oxi- des, such as copper, iron, aluminum, zinc, cobalt and manganese supported over, alumina [8], clays [9], carbons [10], and zeolites [11,12] among others. Additionally, mixed metal oxides, such as M–Zn–Ti–O (M = Mn, Cu, Mo) [13], Fe–Mn–Zn–Ti–O [14], Co–Zn– Al–O [15], Fe–Sb–O and Fe–Sn–O [16] have been studied as H 2 S 1387-1811/$ - see front matter Ó 2012 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.micromeso.2012.09.018 ⇑ Corresponding author. Tel./fax: +58 261 4128791. E-mail address: ajmoronta@gmail.com (A. Moronta). Microporous and Mesoporous Materials 168 (2013) 111–120 Contents lists available at SciVerse ScienceDirect Microporous and Mesoporous Materials journal homepage: www.elsevier.com/locate/micromeso