Formula and preparing method of automobile three-way catalyst

Abstract

The invention discloses a formula and preparing method of an automobile three-way catalyst. The automobile three-way catalyst is characterized by being prepared from, by weight, 80% to 90% of porous ceramic, 5% to 10% of adsorbing agents and 5% to 10% of catalysts; the porous ceramic is prepared from, by weight, 90 parts to 100 parts of alumina sol, 40 parts to 60 parts of micro-nano-grade alpha-Al2O3, 20 parts to 30 parts of pore-forming agents, 0 part to 5 parts of binding agents, 2 parts to 5 parts of adhesion agents and 250 parts to 350 parts of an acid solution with the pH of 3-4; the adsorbing agents comprise single-crystal magnesium oxide. According to the formula and preparing method of the automobile three-way catalyst, the single-crystal magnesium oxide replaces traditional aluminum oxide to serve as the adsorbing agents, and the purifying capacity is 2-3 times that of the aluminum oxide; the porous ceramic with even pores and the high pore forming rate is prepared with an alumina sol / gel method in cooperation with the inorganic salt hole forming agents, the specific surface area of the porous ceramic is large accordingly, the number of catalytic activation loci is large, and purifying capacity is high.

Description

technical field [0001] The invention relates to an automobile three-way catalytic converter formula and a preparation method thereof, belonging to the technical field of environmental protection catalysis. Background technique [0002] The three-way catalytic converter is the most important external purification device installed in the automobile exhaust system. It can convert harmful gases such as CO, HC and NOx emitted from automobile exhaust into harmless carbon dioxide, water and nitrogen. When the high-temperature automobile exhaust gas passes through the purification device, the purification agent in the three-way catalytic converter will enhance the activity of the three gases CO, HC and NOx, and promote them to undergo a certain oxidation-reduction chemical reaction, in which CO is oxidized at high temperature to become non-toxic. Color, non-toxic carbon dioxide gas; HC compounds are oxidized to water and carbon dioxide at high temperature; NOx is reduced to nitroge...

AI Technical Summary

Problems solved by technology

The pore-forming agent of the current carrier is generally an organic pore-forming agent, such as natural fibers, high molecular polymers and organic acids, etc. The organic pore-forming agent decomposes at a temperature much lower than the sintering temperature of the carrier, and leaves pores after decomposition. These pores, Especially some small pores are easy to be closed during the subsequent high-temperature sintering molding, resulting in low porosity of the carrier and poor catalytic ability

[0004] In addition, the adsorbent in the current catalyst generally uses alumina, which can adsorb small molecular polar compounds, such as CO, HC and NOx, and after the adsorption, the catalyst will convert CO, HC and NOx into harmless carbon dioxide and water. and nitrogen; but the adsorption capacity of aluminum oxide is poorer than that of magnesium oxide, so the present invention provides a formula for three-way catalytic converter for automobiles with stronger adsorption capacity for automobile exhaust molecules and its preparation method