Catalyst, Selective Catalytic Reduction (SCR): Description: Description

Fig 1: Selective Catalytic Reduction Catalyst

Courtesy of CHRYSLER GROUP, LLC

The Selective Catalytic Reduction (SCR) is a catalyst element made of low precious metals used in reducing nitrous oxide gases (NOx) to an element of nitrogen. By injecting a Diesel Exhaust Fluid (DEF) solution upstream of a catalyst. The DEF solution will vaporize and decompose to form ammonia and carbon dioxide. When the ammonia vapor is introduced to the NOx gas, it converts it to a harmless nitrogen and water by product.