South Dakota School of Mines & Technology

Presentation

Ammonia Yields during Plasma-Assisted Catalysis Boosted By Hydrogen Sink Effect

Maria Carreon

Plasma-catalytic ammonia synthesis is known since early 1900s but the possible reaction pathways are currently under investigation. In this article, we present the use of various transition metals and gallium-rich alloys for plasma-catalytic ammonia synthesis. The best three metallic catalysts were identified to be Ni, Sn and Au with the highest ammonia yield of 34%. Furthermore, as compared to its constituent metals some alloys presented about 25-50% better yields. The metals employed were classified in two different categories according to their behavior during ammonia plasma-catalysis. Category I metals are nitrophobic and the measured concentration of Hα in the gas phase…

Presentation

Synthesis of Ammonia By RF Non-Thermal Plasma over Ni-MOF-74

Maria Carreon

Herein, we demonstrate a synergistic approach consisting on radiofrequency plasma to synthesize ammonia in the presence of Ni-MOF-74 as catalyst. The Ni-MOF displayed higher ammonia yields as com-pared to the pure Ni metal. Specifically, ammonia yields as high as 0.23 g-NH3 (kWh-g-catalyst)-1 and energy cost of 265 MJ mol-1 over Ni-MOF were observed. The enhanced catalytic activity of the Ni-MOF in the presence of plasma was attributed to the presence of pores that improved mass transfer of guest and product molecules during reaction, the presence of open Ni metal sites, and lower surface hydrogen re-combination. Furthermore, the ammonia energy yield…