Catalytic Ammonia Oxidation Using Ammonia Solution under Electrochemical Conditions: Investigation on Axial Ligand of Ruthenium Catalysts

We have investigated catalytic ammonia oxidation using ruthenium complexes as catalysts under electrochemical conditions. Cyclic voltammetry and bulk electrolysis with an ammonia solution in MeCN are conducted in the presence of a catalytic amount of ruthenium complexes bearing a 2,2′-bipyridine-6,6′-dicarboxylate ligand with various 6-substituted isoquinolines and phthalazine as axial ligands. As a result, the ruthenium complex bearing phthalazines shows the highest catalytic activity at low applied potentials, where up to 319 equivalents of dinitrogen per catalyst are generated.