Japanese chemists have developed a catalyst based on lanthanum nitride with the addition of Nickel, check its ability to accelerate the reaction of formation of ammonia from nitrogen and hydrogen and established the mechanism of the processes. The material allowed the ammonia stably and continuously be produced for 100 hours, and was able to function better than similar materials of the transition metals and is comparable to the more expensive ruthenium catalyst. The results of a study published in Nature.
Ammonia is widely used in industry and is a key component in nitrogen fertilizer production. This substance is produced by the reaction of atmospheric nitrogen with hydrogen, but not directly, and using catalysts that reduce the activation energy of the reaction. Most often it is either expensive metals, or less effective inorganic compounds.
Recently, scientists have shown that nitrides of the transition metals with nitrogen vacancies in the crystal lattice on the surface of the material reduces the binding energy of the nitrogen in the air, favoring its rupture. Tien-Nan E (Tian-Nan Ye) with colleagues from the Tokyo Institute of technology have created a catalyst based on lanthanum nitride with the addition of Nickel and checked its properties. The material consisted of particles with a size of about 30 nanometers.
The catalytic activity of nanomaterial were above five and a half micromol per gram of catalyst per hour at a temperature of 400 degrees Celsius and a pressure of 0.1 MPa. Ammonia formed with constant speed for 100 hours, after which the crystalline structure of the catalyst, the composition of the surface and particle size had not changed. The catalyst showed better analogues based on cobalt and Nickel, and is comparable with catalysts based on expensive ruthenium. The reaction rate growing monotonically with increasing pressure, while poisoning with hydrogen has not been observed.