Experimente mit Erdalkalimetallen

Reactions of the alkaline earth metals magnesium, calcium, strontium, and barium with water, phenolphthalein solution, diluted extract of red cabbage, diluted hydrochloric acid, or ammonia are well suited for a demonstration of the increase in reactivity within this group of metals with increasing atomic number. If the alkali metals lithium and sodium are included, the reactivity of six s‐block elements can be demonstrated in test tubes with small amounts of chemicals.     

Intermetallic Electride Catalyst as a Platform for Ammonia Synthesis

Electrides loaded with transition‐metal (TM) nanoparticles have recently attracted attention as emerging materials for catalytic NH₃ synthesis. However, they suffer from disadvantages associated with the growth and aggregation of nanoparticles. TM‐containing intermetallic electrides appear to be promising catalysts with the advantages of both electrides and transition metals in a single phase. LaRuSi is reported here to be an intermetallic electride with superior activity for NH₃ synthesis, and direct evidence is provided supporting its electride‐character‐induced catalytic performance. The discussion is made mainly based on the contrasting synthesis rates over the isostructural compounds LaRuSi, CaRuSi, and LaRu₂Si₂, and the N₂ isotope‐exchange reactions over these compounds. Lattice hydride ions, which can reversibly exchange with anionic electrons, are shown to be indispensable in the promotion of NH_x formation. The mechanism derived from the present findings provides new guidelines for NH₃ synthesis.