Preparation method of close-coupled three-way catalyst for motor vehicle exhaust purification

The invention discloses a preparation method of a close-coupled three-way catalyst for motor vehicle exhaust purification, belonging to the field of automobile exhaust purification. The preparation method comprises the following steps: firstly dissolving cerium nitrate, zirconium nitrate, lanthanum nitrate and praseodymium nitrate in sequence, adding gamma-Al2O3 during stirring, and then adding hydrogen peroxide and citric acid to prepare a composite material A; dissolving cerium nitrate, zirconium nitrate, lanthanum nitrate and yttrium nitrate in sequence, adding gamma-Al2O3 during stirring,and then adding hydrogen peroxide and citric acid to prepare a composite material B; taking the composite material A and noble metal palladium as a first coating on a honeycomb ceramic carrier, and taking the composite material B and noble metal rhodium as a second coating layer to obtain the catalyst. The high-temperature sintering resistance of the catalyst is improved by formulating the ratio of different rare earths o