Author(s) :

Michael Sulla.

Volume/Issue :

Abstract :

Ammonia (NH3) is a promising candidate for molecular hydrogen storage. To release hydrogen, ammonia must be decomposed in a catalytic decomposition reaction, which often utilizes Ruthenium (Ru) -based catalysts. However, Ru is vulnerable to poisoning from contaminants like Nitrogen Dioxide (NO2), Carbon Dioxide (CO2), and Sulfur Dioxide (SO2), which are often present within ammonia streams. Through the use of density functional theory (DFT) simulations, the adsorption of NO2, CO2, SO2, and NH3 was modeled interacting with Ru and Platinum (Pt) catalyst surfaces. These simulations revealed that Pt is highly vulnerable to NO2 and SO2 poisoning, while exhibiting unfavorable interactions with NH3. As such, our results suggest that Pt is unsuitable as a catalyst for an NH3 decomposition reaction. However, it may still be used as a component to filter NO2 and SO2 contaminants. Ru also exhibits SO2 and NO2 binding modes, but these interactions are comparatively weaker than the Pt surface interactions. In contrast to the Pt surface, the Ru surface did show favorable binding modes with NH3. Overall, these results confirm that Ru-based catalysts are more suitable than Pt-based catalysts for ammonia decomposition, but are still vulnerable, particularly to NO2 and SO2 contaminants.