PREPARATION PROCESS FOR OXIDATION CATALYST FOR PURIFYING THE EXHAUST GAS OF DIESEL ENGINE

摘要

A preparation method of an oxidation catalyst for purifying exhaust gas of a diesel engine, which is satisfactorily operated even at a low exhaust gas temperature to effectively remove particulate matters and soluble organic fractions through combustion, is provided. A preparation method of an oxidation catalyst for purifying exhaust gas of a diesel engine comprises the steps of: (a) agitating titania, beta zeolite having a SiO2/Al2O3 mole ratio of 10 to 400, and aluminosilicate with a silica sol to prepare a composite support mixed solution; (b) wash-coating the composite support mixed solution on a feed-through type ceramic or metallic support; (c) drying or/and firing the wash-coated support; (d) impregnating the dried or/and fired wash-coated support with a catalytic solution containing one or more platinum group compounds selected from a platinum(Pt)-based compound, a palladium(Pd)-based compound, and a rhodium(Rh)-based compound; and (e) drying and firing the impregnated support. The aluminosilicate is an acidic aluminosilicate comprising 70 to 95 wt.% of SiO2 and 5 to 30 wt.% of Al2O3.