Research progress on anti sulfur poisoning technology of catalytic converters

  Industry News     |      2024-04-19

With the increasingly strict environmental regulations, automobile exhaust emission control has become an important research direction in the automotive industry. As a key technology for reducing pollutant emissions in exhaust, catalytic converters have particularly important performance stability and durability. However, sulfur poisoning is a major challenge faced by catalytic converters, seriously affecting their catalytic performance and service life. Therefore, the research on sulfur poisoning resistance technology has become a hot topic in the field of catalytic converters. This article reviews the research progress of catalytic converter anti sulfur poisoning technology in recent years, including the optimization of catalyst materials, exploration of sulfur poisoning mechanisms, development of catalyst regeneration technology, and looks forward to the future research directions of anti sulfur poisoning technology.


Keywords: catalytic converter; Anti sulfur poisoning; Catalyst materials; Mechanism of sulfur poisoning; Catalyst regeneration



1、 Introduction


With the increasingly serious global environmental problems, controlling automobile exhaust emissions has become an important issue for the development of the automotive industry. As a key technology for reducing pollutant emissions in exhaust, the stability and durability of catalytic converters are crucial for achieving efficient purification of automotive exhaust. However, in practical use, catalytic converters often suffer from sulfur poisoning, leading to a decrease in catalytic activity and even complete failure. Therefore, research on sulfur poisoning resistance technology has become an important research direction in the field of catalytic converters.


Sulfur poisoning mainly comes from sulfur-containing compounds in fuel, which produce sulfides during combustion and react with the active components of the catalyst, leading to catalyst poisoning. Sulfur poisoning not only reduces the activity of catalysts, but may also cause phase changes and structural damage, thereby shortening the service life of catalytic converters. Therefore, conducting research on sulfur poisoning resistance technology is of great significance for improving the performance and service life of catalytic converters.


2、 Optimization of catalyst materials


The optimization of catalyst materials is one of the key ways to improve the sulfur poisoning resistance of catalytic converters. In recent years, researchers have improved the sulfur poisoning resistance of catalysts by introducing new active components, adjusting catalyst composition and structure, and optimizing catalyst carriers.


Introduction of new active components

The introduction of new active components is an effective means to improve the sulfur poisoning resistance of catalysts. For example, substances with excellent catalytic activity such as rare earth elements and precious metals are widely used in the preparation of catalysts. These active components can react with sulfides to form stable compounds, thereby reducing the damage of sulfides to catalyst active components. In addition, some new composite oxides also exhibit good resistance to sulfur poisoning, such as spinel structures, perovskite structures, and other composite oxides.


Adjustment of catalyst composition and structure

By adjusting the composition and structure of the catalyst, the surface area, pore structure, and distribution of active sites can be improved, thereby enhancing the catalyst's sulfur poisoning resistance. For example, increasing the specific surface area of a catalyst can provide more active sites and reduce the risk of sulfur poisoning per unit area; Optimizing the pore structure can improve the mass transfer performance of the catalyst and reduce the accumulation of sulfides inside the catalyst; Adjusting the distribution of active components can improve the catalytic activity of catalysts and reduce the impact of sulfur poisoning on catalytic performance.


Optimization of catalyst support

The catalyst carrier has a significant impact on the performance and stability of the catalyst. Optimizing the catalyst carrier can improve the sulfur poisoning resistance of the catalyst. Common catalyst carriers include alumina, diatomaceous earth, zeolite, etc. In recent years, researchers have also developed some new carrier materials, such as carbon nanotubes, mesoporous materials, etc. These new carrier materials have a high specific surface area and good pore structure, which can provide more active sites and better mass transfer performance, thereby improving the sulfur poisoning resistance of the catalyst.


3、 Exploration of the mechanism of sulfur poisoning


A deep understanding of the mechanism of sulfur poisoning is of great significance for developing effective anti sulfur poisoning technologies. In recent years, researchers have conducted in-depth investigations into the mechanism of sulfur poisoning through experiments and theoretical calculations.


Sulfur poisoning mainly occurs on the active components of catalysts, where sulfides undergo chemical reactions with the active components, leading to changes in the structure and properties of the active components. Specifically, sulfides can undergo coordination reactions with metal ions in catalysts, forming stable sulfide complexes; At the same time, sulfides can also react with functional groups such as hydroxyl groups on the surface of catalysts to produce products such as sulfates. These reactions will destroy the active sites of the catalyst and reduce its catalytic activity.


In addition, sulfur poisoning may also cause phase changes and structural damage to the catalyst. Sulfides may react with certain components in the catalyst, leading to changes in the crystal structure of the catalyst and even the formation of new phases. These phase changes may alter the catalytic performance of the catalyst, causing it to lose its original catalytic activity.


4、 Development of catalyst regeneration technology


Catalyst regeneration technology is an important means to improve the service life of catalytic converters and reduce their operating costs. Researchers have developed a series of catalyst regeneration technologies to address the issue of sulfur poisoning.


Hot regeneration is a common catalyst regeneration method that removes surface sulfides by heating the catalyst. However, high temperatures may lead to sintering and structural damage of catalysts, so strict control of regeneration temperature and time is necessary. Chemical regeneration is the process of using chemical reagents to react with sulfides, converting them into soluble substances, and then removing them through washing and other methods. The chemical regeneration method can effectively remove sulfides, but it may have a certain impact on the performance of the catalyst. Therefore, when choosing a regeneration method, it is necessary to comprehensively consider the properties of the catalyst and the degree of sulfur poisoning.


The research on anti sulfur poisoning technology of catalytic converters is of great significance for improving the performance and service life of catalytic converters. In recent years, researchers have made significant progress in optimizing catalyst materials, exploring sulfur poisoning mechanisms, and developing catalyst regeneration technologies. However, anti sulfur poisoning technology still faces some challenges and problems, such as the development of new catalyst materials and a deeper understanding of sulfur poisoning mechanisms