Internal combustion engine tail gas purifying ternary catalyst and preparation method thereof

Abstract

The invention relates to the field of internal combustion engine tail gas treatment, in particular to a ternary catalyst for purifying the tail gas of an internal combustion engine and a preparation method thereof. The preparation method is characterized in that cordierite ceramic honeycomb is used as a carrier, precious metals such as platinum, palladium and rhodium are adopted as active components, the bottom layer catalyst contains the palladium active component with the active component concentration of 0.1 to 6g / L, the content of cerium of a cerium-containing oxygen storage material is 15-30 percent by weight, the top catalyst contains palladium and / or rhodium active component with the concentration of 0.01 to 0.6g / L, the content of cerium of the cerium-containing oxygen storage material is 40 to 80 percent by weight, a heat-resisting oxide is aluminum oxide consisting of gamma-aluminum oxide or theta-aluminum oxide, the aluminum oxide is stabilized by 3 to 8 percent by weight of lanthanum, the specific surface area is 120 to 300 m<2> / g, the weight ratio of the aluminum oxide to cerium-containing oxygen storage material to additive is 100: (40-80): (11-30). By adopting the catalyst based on the technical scheme, the conversion efficiency of the pollutants in tail gas of the internal combustion engine is high, the ignition temperature is lower, and the thermal stability in high temperature is high.

Description

technical field [0001] The invention relates to the field of purification and treatment of exhaust gas of internal combustion engines, in particular to a three-way catalyst for purification of exhaust gas of internal combustion engines and a preparation method thereof. Background technique [0002] The exhaust of internal combustion engines contains a large amount of carbon monoxide, nitrogen oxides and hydrocarbons, which are the main sources of air pollution. At present, the most effective means to prevent and control the exhaust pollution of internal combustion engines at home and abroad is to install a three-way purifier, which uses the synergy of precious metals and other rare earth materials. Under the condition of controlling the air-fuel ratio, the three harmful substances of carbon monoxide, nitrogen oxides and hydrocarbons can be purified at the same time. The core component of the three-way purifier is the three-way catalyst. The three-way catalyst is usually comp...

AI Technical Summary

Problems solved by technology

Although the catalyst preparation process is simple, there is still this major deficiency. Since the noble metal palladium, platinum, and rhodium do not exist separately in space as active components, when they are in direct contact with each other, when they are in high temperature in a lean or rich state will form intermetallic phases and lose catalytic activity

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