Three Way Filter (TWF®)

A Three Way Filter (TWF®) is a gasoline particulate filter (GPF) with a JM catalyst coating. Gasoline vehicles fitted with Johnson Matthey TWF technology can reduce particle numbers by up to 99%.

A TWF also displays catalytic activity, providing significant reductions of gaseous emissions (HC, CO, NOx), as well as filtration of fine particles.

[CO] + O2 → CO2

[HC] + O2 → CO2 + H2O

[NOx] + H2 → N2 + H2O

Composition: Typically precious metals (Pd, Pt or Rh) with alumina and rare earth oxide, coated on filter substrate.

Our Three Way Filters…

  • Have a class-leading combination of low back pressure and high filtration efficiency.

  • Can offer comparable gaseous conversion to a flow-through TWC, as well as promoting soot burn and filter regeneration.

  • Are capable of very high filtration efficiency from the fresh condition to help meet future particulate number requirements.

  • Have tailored coatings optimised to customer needs. They balance filtration, three-way conversion and backpressure performance as well as durability requirements.

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Automotive emissions control

Emissions control for other applications