三元催化器，是安装在汽车排气系统中重要的机外净化装置，它可将汽车尾气排出的CO一氧化碳、HC碳氢化合物和NOx氮氧化物等有害气体通过氧化和还原作用转变为无害的二氧化碳、水和氮气。由于这种催化器可同时将废气中的三种主要有害物质转化为无害物质，故称三元。下面济南沃尔沃汽车维修哪家好人员来讲讲汽车三元催化器失效的原因。

A three-way catalytic converter is an important external purification device installed in the automotive exhaust system. It can convert harmful gases such as CO, HC hydrocarbons, and NOx nitrogen oxides emitted from automotive exhaust into harmless carbon dioxide, water, and nitrogen through oxidation and reduction. Due to the fact that this catalytic converter can simultaneously convert the three main harmful substances in the exhaust gas into harmless substances, it is called ternary. Which good maintenance personnel from Jinan Volvo Cars will explain the reasons for the failure of the three-way catalytic converter in cars.

1.温度过高

1. The temperature is too high

常温下三元催化转化器不具备催化能力，其催化剂必须加热到一定温度才具有氧化或还原的能力，通常催化转化器的起燃温度在250—350℃，正常工作温度一般在350—700℃。

At room temperature, a three-way catalytic converter does not have catalytic ability, and its catalyst must be heated to a certain temperature to have the ability to oxidize or reduce. Usually, the ignition temperature of the catalytic converter is between 250-350 ℃, and the normal operating temperature is generally between 350-700 ℃.

催化转化器工作时会产生大量的自量越高，氧化的温度也愈高，当温度超过850—1000℃时，其内涂层的催化剂很可能会脱落，载体碎裂。所以必须注意控制造成排气温度升高的各种因素，如点火时间过迟或点火次序错乱、断火等，这都会使未燃烧的混合气进入催化反应器，造成排气温度过高，影响催化转化器的效能。

During the operation of catalytic converters, a large amount of self weight will be generated, and the oxidation temperature will also be higher. When the temperature exceeds 850-1000 ℃, the catalyst on its inner coating is likely to fall off and the carrier will shatter. Therefore, it is necessary to pay attention to controlling various factors that cause an increase in exhaust temperature, such as delayed ignition, disordered ignition sequence, and misfire. This can cause unburned mixture to enter the catalytic reactor, resulting in high exhaust temperature and affecting the efficiency of the catalytic converter.

2.慢性中毒

2. Chronic poisoning

催化剂对硫、铅、磷、锌等元素非常敏感，硫和铅来自于汽油，磷和锌来自于润滑油，这四种物质及它们在发动机中燃烧后形成氧化物颗粒易被吸附在催化剂的表面，使催化剂无法与废气接触，从而失去了催化作用，即所谓的“中毒”现象。

Catalysts are very sensitive to elements such as sulfur, lead, phosphorus, and zinc. Sulfur and lead come from gasoline, while phosphorus and zinc come from lubricating oil. These four substances and their oxide particles formed after combustion in the engine are easily adsorbed on the surface of the catalyst, preventing it from coming into contact with exhaust gas and thus losing its catalytic effect, known as the "poisoning" phenomenon.

3.表面积碳

3. Surface area carbon

当汽车长期工作于低温状态时，三元催化器无法启动，发动机排出的炭烟会附着在催化剂的表面，造成无法与CO和HC接触，长期下来，便使载体的孔隙堵塞，影响其转化效能。

When the car is operated at low temperatures for a long time, the three-way catalytic converter cannot start, and the carbon smoke emitted by the engine will adhere to the surface of the catalyst, causing it to be unable to contact CO and HC. Over time, it will block the pores of the carrier and affect its conversion efficiency.

4.排气恶化

4. Exhaust deterioration

催化转化器对污染物的转化能力有一定的限度，因此必须通过机内净化技术将原始排气降到低。如果排放的废气污染物各成分的浓度、总量过大，比如混合气偏浓等，就会影响催化器的催化转化能力，降低其转化效率。此外，由于废气中有大量的HC和CO进入催化反应器后，会在其中产生过度的氧化反应，氧化反应产生大量热量将使催化反应器温度过高而损坏。

The catalytic converter has a certain limit on its ability to convert pollutants, so it is necessary to reduce the original exhaust through internal purification technology. If the concentration and total amount of various components of exhaust pollutants emitted are too high, such as a concentrated mixture, it will affect the catalytic conversion ability of the catalytic converter and reduce its conversion efficiency. In addition, due to the large amount of HC and CO in the exhaust gas entering the catalytic reactor, excessive oxidation reactions will occur, and the large amount of heat generated by the oxidation reaction will cause damage to the catalytic reactor due to excessive temperature.

5.与发动机不匹配

5. Mismatch with engine

即使是同样的发动机，同样的三元催化转化器，车型不同，发动机常用的工作区间就不同，排气状况就发生变化，安装三元催化器的位置就不同，这都会影响三元催化转化器的催化转化效果。因此，不同的车辆，应使用不同的三元催化转化器。

Even with the same engine, the same three-way catalytic converter, and different vehicle models, the commonly used operating range of the engine varies, resulting in changes in exhaust conditions and different installation positions of the three-way catalytic converter. This will affect the catalytic conversion effect of the three-way catalytic converter. Therefore, different vehicles should use different three-way catalytic converters.

6.氧传感路失效

6. Failure of oxygen sensing circuit

为使废气催化率达到佳，必然在发动机排气管中安装氧传感器并实现闭环控制，其工作原理是氧传感器将测得废气中氧的浓度，转换成电信号后发送给ECU，使发动机的空燃比控制在一个狭小的、接近理想的区域内，若空燃比大时，虽然CO和HC的转化率略有提高，但NOx的转化率急剧下降为20%，因此必须保证佳的空燃比，实现佳的空燃比。

In order to achieve optimal exhaust gas catalytic efficiency, an oxygen sensor must be installed in the engine exhaust pipe and closed-loop control must be achieved. Its working principle is that the oxygen sensor will measure the concentration of oxygen in the exhaust gas, convert it into an electrical signal, and send it to the ECU, so that the air fuel ratio of the engine is controlled in a narrow and nearly ideal area. If the air fuel ratio is large, although the conversion rates of CO and HC slightly increase, the conversion rate of NOx sharply decreases to 20%, Therefore, it is necessary to ensure a good air fuel ratio and achieve a good air fuel ratio.

关键是要保证氧传感器工作正常。如果燃油中含铅、硅就会造成氧传感器中毒。此外使用不当，还会造成氧传感器积碳、陶瓷碎裂、加热器电阻丝烧断、内部线路断脱等故障。氧传感器的失效会导致空燃比失准，排气状况恶化，催化转化器效率降低，长时间会使催化转化器的使用寿命降低。更多相关事项就来我们网站http://www.lutongqixiu.com进行了解！

The key is to ensure that the oxygen sensor operates normally. If the fuel contains lead and silicon, it can cause oxygen sensor poisoning. In addition, improper use can also cause faults such as carbon deposition, ceramic fragmentation, heater resistance wire burning, and internal circuit disconnection of the oxygen sensor. The failure of oxygen sensors can lead to inaccurate air fuel ratio, deterioration of exhaust conditions, reduced efficiency of catalytic converters, and prolonged service life of catalytic converters. For more related matters, come to our website http://www.lutongqixiu.com Get to know!