Researchers are investigating the role neutrons could play in developing particulate matter filters for petrol vehicles to reduce air pollution.

A team of researchers at the Department of Energy’s (DOE’s) Oak Ridge National Laboratory (ORNL) are studying soot collection and removal in particulate filters with neutron imaging, a technique able to detect very fine layers of material.

US emissions regulations have required particulate filters to control soot from diesel vehicles since 2007 – now researchers are investigating how to use these filters for petrol engines, which release smaller particles.

Filters can be restored to their original state by removing build-ups of carbon-based material through heat treatment and oxidation, which researchers suggest could enable them to be self-cleaning and thus ensure they work more effectively for a longer duration.

Todd Toops, Emission and Emissions Control Technical Lead at the ORNL, said: “The purpose of our research is enabling more fuel efficient vehicles, whether that’s understanding how the soot regenerates in diesel vehicles to improve fuel economy or evaluating how a future gasoline filter would handle soot.”