What is the purpose of adding urea in large vehicles?

[SanFaith]

Adding urea in large vehicles serves the purpose of catalysis and conversion. The reasons are as follows: 1. Urea is specifically used for diesel engines because diesel engines emit harmful nitrogen oxide gases during operation, which are detrimental to the atmosphere and human health. Long-term exposure to such gases can cause respiratory diseases. 2. To reduce the harm of these gases to the atmosphere and humans, urea is utilized. When added, it triggers a catalytic reaction. 3. When urea encounters nitrogen oxide gases emitted by diesel engines, a chemical reaction occurs, converting the nitrogen oxides into nitrogen and water, which are harmless to the atmosphere and human health.