| 摘要 |
A hydrotalcite-zeolite composite comprising an alkali or alkali earth metal ion-exchanged zeolite and a transition metal-substituted hydrotalcite is provided, a method for preparing the hydrotalcite-zeolite composite is provided, and an NOx storage catalyst is provided to improve the NOx storage capacity and obtain excellent thermal and mechanical stabilities and excellent poisoning resistance to sulfur dioxide by using the composite. A preparation method of a hydrotalcite-zeolite composite comprises the steps of: separately preparing core mother liquids of a zeolite and a hydrotalcite; and mixing the zeolite core mother liquid and the hydrotalcite core mother liquid, and subjecting the mixture to a hydrothermal reaction. The preparation method further comprises the step of supporting one or more platinum group metals on a support. The zeolite is analcime, mordenite type zeolite, or zeolite Y. The transition metal substituted for the hydrotalcite is cobalt, cerium, copper, iron, or nickel. The hydrothermal reaction step is carried out a 90 to 120 deg.C for 4 to 12 hours. An Nox storage zeolite-hydrotalcite composite is prepared by the preparation method of a hydrotalcite-zeolite composite comprising the steps of: separately preparing core mother liquids of a zeolite and a hydrotalcite; and mixing the zeolite core mother liquid and the hydrotalcite core mother liquid, and subjecting the mixture to a hydrothermal reaction. An Nox storage zeolite-hydrotalcite composite catalyst is prepared by the preparation method of a hydrotalcite-zeolite composite comprising the step of supporting one or more platinum group metals on a support.
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