A kind of preparation method of formula of high activity automobile three-way catalytic converter

Abstract

The invention discloses a high-activity automobile three-way catalyst formula and a preparation method thereof. The high-activity automobile three-way catalyst formula is characterized by comprising 80 wt%-90 wt% of porous ceramic, 5 wt%-10 wt% of adsorbent and 5 wt%-10 wt% of catalysts, the porous ceramic is prepared from, by weight, 90-100 parts of alumina sol, 40-60 parts of micro-nano-scale alpha-Al2O3, 20-30 parts of pore-forming agents, 0-5 parts of binding agents, 2-5 parts of adhesives and 250-350 parts of acid solutions with the pH of 3-4, and the absorbing agents include magnetic chitosan nanoparticles. According to the high-activity automobile three-way catalyst formula and the preparation method, the magnetic chitosan nanoparticles replace traditional aluminium oxide to serve as the absorbing agents, the automobile tail gas molecule adsorption capacity of the magnetic chitosan nanoparticles is higher, the purification capacity of the magnetic chitosan nanoparticles is 5-10 times of the purification capacity of aluminum oxide, iron on the surfaces of chitosan has desulfuration activity, and a three-way catalyst is effectively prevented from sulfur poisoning.

Description

technical field [0001] The invention relates to a method for preparing a formula of a high-activity three-way catalytic converter for automobiles, and belongs 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 red...

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; however, alumina has problems such as weak adsorption capacity, easy diffusion and rearrangement of aluminum particles, and easy sulfur poisoning.