In a fresh advertising initiative for its hydrogen fuel cell vehicle, the Mirai, Toyota is launching pollution-reducing billboards throughout California. The billboards are coated with a vinyl infused with titanium dioxide, which functions similarly to a car’s catalytic converter. When exposed to light, humidity, and wind, this coating interacts with nitrogen dioxide (NO2) in the atmosphere, effectively eliminating the nitrogen and leaving oxygen behind. NO2 is a particularly harmful pollutant that can cause various respiratory issues, including asthma, and is also a contributor to acid rain. One of the primary sources of NO2 pollution is exhaust from gasoline and diesel vehicles.
Beginning April 3rd, 37 of these “Eco-billboards” will be installed in Los Angeles and San Francisco for an eight-week period. According to Toyota, this initiative will provide “24,960 square feet of pollution-filtering surface,” effectively compensating for the nitrogen dioxide (NOx) emissions of approximately 5,285 vehicles each month. The innovative billboard vinyl is a product of PURETi Group, which hopes other advertisers will adopt this eco-friendly material. Toyota showcased the titanium dioxide-coated vinyl by wrapping a Mirai in it during the Environmental Media Association Impact Summit.
While this technology is impressive and innovative, it raises certain questions. What will happen to the billboards when they are taken down? Nitrogen itself is valuable and beneficial. Is there a plan for recycling or reusing the coated vinyl? Can the nitrogen be extracted for other uses? These concerns are more inquiries than accusations. I have reached out to PURETi and will provide updates to this article upon receiving a response.
UPDATE
Glen Finkel from PURETi addressed my questions via email (formatted in italics below):
Is it possible to separate the titanium dioxide for reuse?
“No, and this is not necessary. PURETi works with a very small amount of titanium dioxide, making it highly efficient.
For perspective, a gallon of conventional paint contains around a pound and a half of titanium dioxide (the white pigment) and covers 300-400 square feet. In contrast, a gallon of PURETi contains just over one ounce of titanium dioxide and can treat between 3,000 and 4,000 square feet.”
What happens to the nitrogen in the process?
“NOx, which is a greenhouse gas and a major factor in acid rain and smog formation, is transformed through the catalytic process into a small quantity of relatively harmless nitrates that are safely washed into the ground.”
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