Browse Publications Technical Papers 2017-01-0946
2017-03-28

Impact of Hydrothermal Aging on the Formation and Decomposition of Ammonium Nitrate on a Cu/zeolite SCR Catalyst 2017-01-0946

Low-temperature (T ≤ 200°C) NOx conversion is receiving increasing research attention due to continued potential reductions in regulated NOx emissions from diesel engines. At these temperatures, ammonium salts (e.g., ammonium nitrate, ammonium (bi)sulfate, etc.) can form as a result of interactions between NH3 and NOx or SOx, respectively. The formation of these salts can reduce the availability of NH3 for NOx conversion, block active catalyst sites, and result in the formation of N2O, a regulated Greenhouse Gas (GHG). In this study, we investigate the effect of hydrothermal aging on the formation and decomposition of ammonium nitrate on a state-of-the-art Cu/zeolite selective catalytic reduction (SCR) catalyst. Reactor-based constant-temperature ammonium nitrate formation, temperature programmed oxidation (TPO), and NO titration experiments are used to characterize the effect of hydrothermal aging from 600 to 950°C. N2 adsorption (BET) surface area and diffuse reflectance Fourier transform infrared spectroscopy (DRIFTS) experiments are also conducted in order to correlate the morphological effects of hydrothermal aging with concomitant changes in ammonium nitrate chemistry. The insights provided herein support the diesel aftertreatment communities’ ongoing efforts to understand low-temperature chemical processes such as ammonium salt formation and their impact on emissions.

SAE MOBILUS

Subscribers can view annotate, and download all of SAE's content. Learn More »

Access SAE MOBILUS »

Members save up to 18% off list price.
Login to see discount.
We also recommend:
JOURNAL ARTICLE

Effect of Transition Metal Ion Properties on the Catalytic Functions and Sulfation Behavior of Zeolite-Based SCR Catalysts

2017-01-0939

View Details

TECHNICAL PAPER

Detailed Mechanism of S Poisoning and De-Sulfation Treatment of Cu-SCR Catalyst

2017-01-0944

View Details

TECHNICAL PAPER

Analysis of TWC Characteristics in a Euro6 Gasoline Light Duty Vehicle

2019-24-0162

View Details

X