In the nickel-rich region of the periodic table, there are a number of compounds that have been difficult to obtain as phase-pure bulk samples. This is because of the materials transport problem during the crystal growth process. However, researchers have used computational methods to identify intermetallic compounds and to synthesize catalysts. They have found a number of promising candidates, including nickel gallium.
Among them, a newly discovered nickel gallium superlattice is highly active in semihydrogenation reactions. The superlattice forms peritectically at 1210 deg C. Its atomic structure is shaped like a triangle. As a result, it may have an unusual magnetic liquid state at low temperatures.
To investigate the effects of Ga on the stability of the Ni-CO interaction, the authors tested a series of cyanoborate ionic liquids. Their reaction medium had an equimolar ratio of Ni(COD)2 and GaCp*. After two weeks, the samples were not agglomerated and showed excellent stability.
To further study the intermetallic properties, scientists at the Technical University of Denmark (TUD) synthesized a solid nickel-gallium catalyst. The results show that the catalyst is efficient in converting carbon dioxide and hydrogen to methanol at room temperature. A smaller number of side products is produced by this catalyst, compared to a conventional one.
The researchers have also measured the liquid-phase product with NMR. Their measurements revealed that the nickel to gallium ratio is 47:53 atoms. These findings indicate that the new nickel gallium compound is the most promising candidate.