Preparation and characterization of very highly dispersed iridium on Al2O3 and SiO2

摘要: To obtain highly dispersed alumina- and silica-supported iridium catalysts, two preparation methods, the incipient wetness method urea technique, were investigated. Hydrogen carbon monoxide chemisorption clearly showed that on γ-Al2O3 resulted in catalysts with a very high dispersion (H/Ir > 2.0 for loadings 1.0 up to 6.8 wt% Ir), contrast made by this technique SiO2 < Ir between 0.4 7.0 Ir). Temperature programmed reduction, desorption oxidation studies supported conclusion. The behaviour of these systems oxygen at elevated temperature also demonstrates stronger interaction alumina. difference is caused diffences adsorption processes during impregnation. Using Ir/SiO2 Ir/Al2O3 obtained = 1.6 1.5 H/Ir 1.2 5.5 Ir/SiO2, 2.5 5.7 Ir/Al2O3). Thus, proved successful Al2O3, whereas both supports.