did you know vehicles radiators can be coated with an ozone reducing catalytic coating? Manganese oxide, a catalyst, not consumed during the conversion of ozone; therefore the catalyst’s lifetime is extensive, usually several years.

 as it drives along, it reduces ozone, a component of smog, capturing about 75 percent of ground-level ozone and converts it to ordinary oxygen

The New York Times had an article on it in 2000

in the 1990s, Volvo worked with New Jersey-based catalyst company Engelhard to use the radiator as a sort of "filter" for smog-producing, ground-level ozone that passed through it in a system called PremAir.

Ford tested the smog-eating radiator concept in 1995 and was, for a time, enthusiastic about the prospects for PremAir. Engelhard said Ford found no technological or cost problems with the technology.

The problem was volume.

Ford said that not enough air passes through a radiator to make much of a difference in fighting air pollution.

the coating Ford rejected cleaned up not just ozone but also carbon monoxide (presumably turning it into carbon dioxide), and thus included precious metals like platinum that would have added between $500 and $1,000 to the cost of each vehicle. 

Volvo's PremAir coating, the representative went on, only added about $50 per car because it focused solely on ozone reduction, and required just a cheaper "base-metal catalyst." 

https://ww2.arb.ca.gov/sites/default/files/classic/msprog/nvepb/macs/_MACs/mac9906/att.pdf#:~:text=While%20this%20MAC%20is%20drafted,manufacturer%20seeking%20to%20certify%20other
https://www.nytimes.com/2000/01/14/automobiles/autos-on-friday-technology-carmakers-to-put-smog-eating-radiator-in-some-models.html

https://www.jalopnik.com/how-volvo-once-used-a-catalyst-coated-radiator-to-remov-1831438959/

https://scholar.lib.vt.edu/VA-news/VA-Pilot/issues/1996/vp960304/03020081.htm

https://www.autonews.com/article/19950410/ANA/504100782/makers-study-catalytic-radiator/

https://wcponline.com/2001/03/15/catalytic-destruction-ozone-cost-effective-approach-controlling-off-gas-ozone-emissions/

What is ozone?

Ozone is the second most powerful oxidizing agent, exceeded in its oxidation potential only by fluorine—which is not used commercially. It is used extensively in water treatment as a disinfecting agent and as an oxidizing agent to assist in the removal of organic and inorganic contaminants, as well as viruses and bacteria.

All the science stuff about ozone? https://wcponline.com/2001/03/15/catalytic-destruction-ozone-cost-effective-approach-controlling-off-gas-ozone-emissions/