Integrated automobile tail gas purification three-way catalyst and preparation method thereof

Abstract

The invention discloses an integrated automobile tail gas purification three-way catalyst and a preparation method thereof. The catalyst includes a first carrier cordierite honeycomb ceramic, a second carrier aluminum source and an active component. The second carrier aluminum source and the active component form a coating of the catalyst, wherein the active component is a composite metal oxide. The preparation method particularly includes following steps: coating the first carrier cordierite honeycomb ceramic, which is corroded by an acid, with the aluminum source through a microwave heating technology; coating the carriers with a salt solution of the active component through an impregnation method; and performing a drying and roasting process to obtain the catalyst. The catalyst is free of usage of precious metals such as platinum, palladium, rhodium and the like, is low in cost, is stable and uniform in coating distribution, is low in initiation temperature, is wide in activity temperature window, is good in a high-temperature-resistant thermal stability and has a good application prospect.

Description

technical field [0001] The invention belongs to the field of air pollution control and environmental protection catalytic materials, and in particular relates to an integral three-way catalyst for automobile tail gas purification and a preparation method thereof. Background technique [0002] With the increase in the use of automobiles, a large number of automobile exhaust emissions pose a serious threat to the ecological environment and become the main factor affecting urban air pollution. The installation of automobile exhaust purification device is the main means to control exhaust pollution. The three-way catalyst is the core part of the device, which can catalyze and purify CO, HC and NO in automobile exhaust at the same time. X Three harmful gases. At present, the active components of three-way catalysts can be divided into three categories: noble metals, metals or metal oxides, and ion-exchanged zeolites. Noble metal catalysts have poor selectivity and narrow active...

AI Technical Summary

Problems solved by technology

Noble metal catalysts have poor selectivity and narrow active temperature range; zeolite catalysts have poor hydrothermal stability; single metal or metal oxide catalysts are unstable at high temperatures and have low catalytic activity

The above-mentioned catalysts have their own shortcomings and are difficult to meet the actual production needs, so the use of non-noble metals or compound active components makes them have better thermal stability, lower light-off temperature, and a wider range of active temperatures. Attracting more and more researchers' attention

[0003] Patent CN102389819A discloses an automobile exhaust catalyst containing cordierite ceramic carrier and CuO additive and its preparation method. The catalyst has low toxicity and high catalytic activity, but the activity at low temperature is poor, and the ignition temperature of NO and CO is relatively high

Patent CN103433057A discloses a three-way catalyst for automobile exhaust purification and its preparation method, with cordierite honeycomb ceramics as the carrier, and γ-A1 2 o 3 The mixture coating with rare earth composite oxide is used as a cocatalyst, and the transition metals Co, Ni and noble metals Pd, Rh are used as catalytic active components. The catalyst shows high three-way catalytic activity and excellent low-temperature ignition performance, but The Pd and Rh contained are expensive, and the resources are scarce, and the active components of the catalyst prepared by the common impregnation method are easy to lose, thus affecting the catalytic activity and catalytic life

Images