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Phys Chem Chem Phys

Title:		Synergistic effects of Ir-Au/TiO(2) catalysts in the total oxidation of propene: influence of the activation conditions
Author(s):		Aguilar-Tapia A; Zanella R; Calers C; Louis C; Delannoy L;
Address:		"Centro de Ciencias Aplicadas y Desarrollo Tecnologico (CCADET), Universidad Nacional Autonoma de Mexico (UNAM), Mexico D. F., Mexico A. P. 70-186. rodolfo.zanella@ccadet.unam.mx"
Journal Title:		Phys Chem Chem Phys
Year:		2015
Volume:		20150318
Issue:		42
Page Number:		28022 - 28032
DOI:		10.1039/c5cp00590f
ISSN/ISBN:		1463-9084 (Electronic) 1463-9076 (Linking)
Abstract:		"Iridium was added to the Au/TiO2 system to try to enhance its catalytic activity in the reaction of propene oxidation, performed under conditions close to those used in the studies of decomposition of volatile organic compounds (1200 ppm propene and 9 vol% O2 in He). Titania supported Ir-Au (Ir/Au = 1) was prepared by sequential deposition-precipitation with urea (DPU) of Ir then Au. The effect of the activation conditions (hydrogen or air at 400 degrees C) was investigated. The study of the activation conditions of Ir-Au/TiO2 showed that activation under hydrogen at 400 degrees C generated a catalyst more active than the monometallic ones, while Ir-Au/TiO2 activated in air remained as poorly active as Au/TiO2. TEM characterization showed the formation of metallic particles of similar size (2-3 nm) in both monometallic Au/TiO2 and bimetallic Ir-Au/TiO2. Characterization especially by DRIFTS using CO as a probe molecule suggests the presence of Ir-Au interaction, IrO2-Au(0) interaction when the sample is calcined and Ir(0)-Au(0) bimetallic particles when it is reduced. XPS and TPR characterization techniques showed that gold hinders to some extent the reoxidation of iridium in the reduced bimetallic Ir-Au/TiO2 catalyst. The enhanced catalytic activity of the reduced bimetallic Ir-Au/TiO2 catalyst is attributed to a surface Ir(0)-Au(0) synergism"
Keywords:
Notes:		"PubMed-not-MEDLINEAguilar-Tapia, Antonio Zanella, Rodolfo Calers, Christophe Louis, Catherine Delannoy, Laurent eng England 2015/03/19 Phys Chem Chem Phys. 2015 Nov 14; 17(42):28022-32. doi: 10.1039/c5cp00590f. Epub 2015 Mar 18"