This is why modern diesels use DEF. It's just hot Urea solution that is sprayed through the diesel exhaust stream which reacts with the NOX after the first pass

This is why modern diesels use DEF. It's just hot Urea solution that is sprayed through the diesel exhaust stream which reacts with the NOX after the first pass through the diesel oxidation catalyst. Urea and the nitrous oxide become nitrogen, water, and CO2. Hydrogen engines may need to use a DEF process like diesels eventually. Especially since hydrogen combustion is really good at making NOX. https://www.autoserviceprofessional.com/articles/7257-diesel-exhaust-fluid-fluid-injection-for-nox-reduction https://www.autoserviceprofessional.com/articles/7257-diesel... https://www.capitalremanexchange.com/20-facts-you-need-to-know-about-diesel-exhaust-fluid-def/ https://www.capitalremanexchange.com/20-facts-you-need-to-kn...