Abstract: The present disclosure describes a catalytic aftertreatment system that includes a dosing compartment including a doser configured to introduce a diesel exhaust fluid (DEF) including urea into a diesel exhaust; a mixing chamber subsequent to the doser configured to mix the DEF with the diesel exhaust, the mixing chamber including an optional static metallic mixer, and a catalyst substrate including a combined urea hydrolysis-selective catalytic reduction binary catalyst coated thereon; and a SCR unit subsequent to the mixing chamber unit, including an SCR catalyst configured to facilitate reduction of nitrogen oxide (NOx) in the diesel exhaust with NH3.