Palladium Gasoline Particulate Filter GPF Catalyst Reduces Gasoline Sulfur PN Filtration

GPF (Gasoline Particulate Filter)Euro 6 PN Filtration for After-treatment System

GPF (Gasoline Particulate Filter)

Gasoline Particulate Filter: GPF (Gasoline Particulate Filter) is a ceramic filter installed in the exhaust system of a gasoline engine. It can capture particulate emissions before they enter the atmosphere.

With upcoming legislations in Europe and China requiring compliance with a particle number (PN) limit of 6*10¹¹/km, particulate filters will be applied for gasoline engines. It is favorable to combine the catalytic activity for the conversion of gaseous pollutants with the reduction of particulates in one step. This can be achieved with catalysed gasoline particlulate filters (cGPF).

1. GPF structure and materials used:

For wall flow structure, GPF generally uses Cd (cordierite).

2. The principle of particle capture by GPF:

• The composition of particulate matter: insoluble particles and soluble particles, mainly from particles produced by incomplete combustion of fuel, fuel additives and lubricants
• Particles mainly exist in three forms: nucleated state; aggregated state; coarse particles
• Gasoline particles are mainly distributed between 70-100nm. There are three principles of trapping particles: diffusion mechanism, interception mechanism, and inertial collision mechanism. The three mechanisms cooperate with each other and are not completely independent.

The working principle of the cGPF is comparable to the well-established catalyzed diesel particulate filters (cDPF). Particulate matter is removed from the exhaust by physical filtration using a honeycomb structure similar to an emissions catalyst substrate but with the channels blocked at alternate ends. The exhaust gas is thus forced to flow through the porous walls between the channels and the particulate matter is deposited on and in the walls. The catalytic coating provides TWC activity and converts CO, HC and NO_x simultaneously.

To meet Euro 6 / China-VI stage light-duty vehicles PN emission requirements, WFEC developed WFG series cGPF catalysts. WFEC cGPF catalysts can achieve excellent PN filtration rate through optimized washcoat design and distribution. By improve of washcoat material and coating process, the backpressure of cGPF catalyst is largely decreased, thus the negative influence on engine fuel economy by cGPF is obvious lowered. And the active catalytic washcoat on cGPF can deeply purify gas pollutant (such as THC, CO and NO_x) and fulfill Euro 6 / China-VI aging requirements. cGPF can install in CC (Close-coupled) or UF (Under-floor) position, applying together with TWC. The vehicle emission of PN and gas pollutant is able to completely satisfy Euro 6 / China-VI regulations after employing WFEC TWC+cGPF aftertreatment system.