Ammonia

About: Ammonia is a research topic. Over the lifetime, 16217 publications have been published within this topic receiving 271940 citations. The topic is also known as: NH3 & azane.

Ammonia decomposition over Ni/La2O3 catalyst for on-site generation of hydrogen

Abstract: Ammonia decomposition is a promising process for on-site generation of hydrogen. In this study, various nickel catalysts supported on metal oxides were prepared and their catalytic activity for ammonia decomposition was investigated. Ni/Al 2 O 3 catalyst achieved the highest ammonia conversion among catalysts investigated due to the high surface area of Al 2 O 3 support (200 m 2 g −1 ). Despite the low surface area of support material (4.7 m 2 g −1 ), the catalytic activity of Ni/La 2 O 3 was comparable to that of Ni/Al 2 O 3 . The basicity of support materials was not specifically related with the catalytic activity. For Ni/La 2 O 3 catalyst, the small nickel particles were deposited over La 2 O 3 from LaNiO 3 during the reduction treatment. When the Ni loading amount was changed in the range of 10–70 wt% for Ni/La 2 O 3 catalyst, the sample with 40 wt% Ni exhibited the highest conversion of 78.9% at 550 °C. The catalytic performance of Ni/La 2 O 3 was also affected by the preparation method and calcination temperature. The LaNiO 3 formation was responsible for the high activity of Ni/La 2 O 3 catalyst for the ammonia decomposition.

Catalytic Effects of Metal-loaded Membrane-like Alumina Tubes on Ammonia Synthesis in Atmospheric Pressure Plasma by Dielectric Barrier Discharge

Abstract: Plasma synthesis of ammonia was studied at atmospheric pressure using a dielectric-barrier-discharge-plasma reactor equipped with a metal-loaded membrane-like alumina tube as a catalyst between the electrodes. Introducing the pure alumina into N2–H2 plasma resulted in an increase in the ammonia yield and the further improvement was achieved by loading the alumina with Ru, Pt, Ni, and Fe. These results clearly demonstrate the catalytic effects of the alumina and the metals in the plasma reaction. Temperature-programmed desorption and isotope exchange reaction of nitrogen revealed that plasma-excited N2 molecules were subjected to dissociative adsorptions mainly on the alumina to form atomic N(a) (The suffix “(a)” denotes adsorbed species) species, which were converted into ammonia by H2 plasma. A role of the metals is considered to be acceleration of ammonia formation by the reaction of the alumina-adsorbed N(a) atoms with plasma-activated hydrogen species.