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In this study, the formation and decomposition of ammonium nitrate (AN) on a state-of-the-art extruded vanadium-based SCR catalyst (V-SCR) under simulated exhaust conditions has been evaluated. Results show that AN readily forms and accumulates at temperatures below 200°C when exposed to NH3 and NO2. The rate of AN accumulation increases with decreasing temperature. A new low temperature NH3 release peak (not present following NH3 storage conditions with NH3 only) becomes apparent after AN accumulation at 100 and 125°C. This new NH3 release, with a peak release temperature of approximately 180°C, is evaluated in detail to better determine its origin. BET surface area, and thermal gravimetric analysis/differential scanning calorimetry (TGA/DSC), and reactor-based experiments are all used to characterize AN formed on the V-SCR catalyst in comparison to pure AN.