title: Reactive adsorption of SO2 on activated carbons with deposited iron nanoparticles.
abstract: The effect of iron particle size anchored on the surface of commercial activated carbon on the removal of SO(2) from a gas phase was studied. Nanosize iron particles were deposited using forced hydrolysis of FeCl(3) with or without H(3)PO(4) as a capping agent. Dynamic adsorption experiments were carried out on either dry or pre-humidified materials and the adsorption capacities were calculated. The surface of the initial and exhausted materials was extensively characterized by microscopic, porosity, thermogravimetric and surface chemistry. The results indicate that the SO(2) adsorption capacity increased two and half times after the prehumidification process owing to the formation of H(2)SO(4) in the porous system. Iron species enhance the SO(2) adsorption capacity only when very small nanoparticles are deposited on the pore walls as a thin layer. Large iron nanoparticles block the ultramicropores decreasing the accessibility of the active sites and consuming oxygen that rest adsorption centers for SO(2) molecules. Iron nanoparticles of about 3-4 nm provide highly dispersed adsorption sites for SO(2) molecules and thus increase the adsorption capacity of about 80%. Fe(2)(SO(4))(3) was detected on the surface of exhausted samples.
authors: Instituto Potosino de Investigación Científica y Tecnológica A.C., División de Ciencias Ambientales, Camino a la Presa San José 2055, Col. Lomas 4a sección, San Luis Potosí SLP 78216, Mexico.
authors: Javier A
authors: JA
authors: Arcibar-Orozco
authors: J Rene
authors: JR
authors: Rangel-Mendez
authors: Teresa J
authors: TJ
authors: Bandosz
mesh_terms: D000327:Adsorption; D000393:Air Pollutants / Q000302:isolation & purification*; D002606:Charcoal / Q000737:chemistry*; D005290:Ferric Compounds / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D013458:Sulfur Dioxide / Q000302:isolation & purification*
chemical_list: D000393:Air Pollutants; D005290:Ferric Compounds; D013458:Sulfur Dioxide; D002606:Charcoal; C021024:ferric hydroxide