| 简介 |
FIELD : chemistry.SUBSTANCE : invention relates to an oxide compound containing cerium oxide, rare-earth metal oxide other than cerium, at least one oxide selected from aluminium oxide and zirconium oxide; and silicon oxide, rare-earth metal other than cerium, is selected from yttrium, lanthanum, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium and mixtures of two or more of them, cerium and said other elements, different from cerium, and silicon are present in weight ratio of 85 : 15 to 99 : 1, in terms of oxides; content of silicon is 1-20 pts.wt, in terms of SiO2, on total 100 weight parts of said other elements, different from silicon, in terms of oxides, and characterised by that during measurement of temperature-programmed reduction (TPR) in an atmosphere of 10 % of hydrogen - 90 % of argon at temperature 50-900 °C with rate of temperature increase 10°C/min with subsequent oxidation treatment at temperature of 500 °C for 0.5 hour, after which measurement of temperature-programmed recovery is performed again, calculated degree of recovery at temperature 400 °C and below is at least 2.0 %, after three repeating said measurements of temperature-programmed reduction and oxidative treatment of its BET specific surface area is at least 30 m2/g, recovery rate is calculated according to following equation : degree of reduction (%) = hydrogen absorption measured sample at a temperature of 400 °C and lower (mcmol/l)/theoretical hydrogen absorption cerium oxide in sample (mcmol/g) × 100. Invention also relates to methods (versions) of producing disclosed composite oxide and to a catalyst for cleaning exhaust gases, equipped with composite oxide.EFFECT : technical result is producing a composite oxide suitable for producing catalysts for cleaning exhaust gases, characterised by excellent heat resistance.10 cl, 1 tbl, 3 ex |
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