In the journey towards green development in the automotive industry, particulate filters have become an important tool for reducing vehicle emissions. However, they have also brought problems such as increased fuel consumption and reduced power to many car owners, and people are beginning to look forward to their early retirement. However, from the actual situation, it is difficult to remove particle traps in the short term because there are many complex development processes behind them. It is a process of the automotive industry constantly adapting to environmental protection needs and continuous technological innovation. Its appearance time varies due to the differences between diesel and gasoline engines:

Firstly, diesel particulate filter (DPF): DPF can be traced back to 1985 when Mercedes Benz applied it to a 3.0L turbocharged engine using a passive regeneration strategy, which utilizes the heat generated by normal engine operation to burn the captured particulate matter. But this attempt was not successful because the exhaust back pressure was too high, resulting in a significant decrease in engine power and affecting vehicle performance. Therefore, DPF technology did not receive sufficient attention in the following years. Later in the late 1990s, the situation took a turn for the better. The Environment Zones Act issued by Sweden requires heavy trucks to be equipped with DPF, which has provided an opportunity for the development of this technology. Car companies and researchers have begun to conduct in-depth research and improve the design and regeneration technology of DPF to overcome early problems.

Entering the 21st century, global environmental awareness continues to increase, and countries and regions such as Europe, America, and Japan are gradually introducing stricter emission regulations, placing extremely high demands on particulate matter (PM) emissions in diesel vehicle exhaust. For example, Euro IV/V regulations require a tailpipe PM of less than 0.02g/kwh. In this context, DPF technology has been widely applied and has become a key equipment for diesel vehicles to meet emission standards. Nowadays, wall flow particulate filters are the mainstream type of DPF, and their carrier adopts a closed wall flow structure, which can efficiently intercept and capture particles. The regeneration methods are divided into active regeneration and passive regeneration. Active regeneration is the process of increasing the exhaust temperature by applying external energy, such as electric heating, fuel injection, etc., to promote the combustion of particulate matter; Passive regeneration is the use of catalysts to reduce the combustion temperature of particulate matter, allowing it to burn at the exhaust temperature during normal engine operation.

Subsequently, gasoline particulate filters (GPFs) were introduced: in the early days, traditional intake fuel injection (PFI) engines emitted less particulate matter, so there were no particulate emission limits for gasoline engines. But with the rise of gasoline direct injection (GDI) engine technology, it has shown outstanding performance in improving torque and power output, and reducing carbon dioxide emissions, gradually becoming mainstream. However, the issue of particulate matter emissions from GDI engines has also become prominent.

In 2009, Euro 5 standards introduced particulate matter mass (pm) limits for gasoline engine vehicles. Although only the particulate matter quantity (pn) for diesel engine vehicles was specified at that time, this marked the beginning of particulate matter emission control for gasoline engines. Subsequently, the Euro 6 standard gradually implemented PN limit regulations for gasoline engines. In the Euro 6c standard that came into effect in September 2017, the particulate matter index for GDI engines was set at 6 × 10 ¹¹#/km, replacing the initial limit of 6 × 10 ¹² #/km. Moreover, Europe has introduced the Real Driving Emissions (RDE) testing program, which requires cars not only to be tested in chassis dynamometer tests, but also to be tested through portable emission measurement systems under real living conditions, posing a higher challenge to the control of particulate matter emissions from gasoline engines.

In response to these stringent emission standards, major vehicle manufacturers have started installing gasoline particulate filters (GPFs). GPF is a wall flow particle capture device with many parallel channels inside the filter body. One of the adjacent channels is only open at the inlet, and the other is only open at the outlet. The exhaust flows into the open inlet channel and is discharged through the porous wall of the GPF carrier to adjacent channels, while particulate matter is trapped in the channels to achieve capture. When the particles in GPF accumulate to a certain extent, by adjusting the engine operating conditions, such as cutting off fuel, delaying ignition angle, etc., the particles in GPF are oxidized and burned, that is, GPF regeneration, removing the particles in GPF, and ultimately achieving a virtuous cycle of "capture regeneration capture".

China has been issuing the National VI emission standards since June 2017. Firstly, the new Volkswagen Tiguan 1.4L TSI engine and Audi A5 2.0 TFSI engine were the first to be equipped with GPF. Subsequently, more and more car companies have applied this technology to their models.