Preparation, characterization and electrocatalysis performance of a trimeric ruthenium-substituted isopolytungstate.

A trimeric ruthenium-substituted isopolyoxotungstate compound Rb10K3H6[SeO3(H9RuW30.5O114)]Cl3·48H2O (1) was synthesised using the hydrothermal method. The synthesized compound was thoroughly characterized by elemental analysis, single-crystal X-ray diffraction, and electrospray ionization and mass spectrometry (ESI-MS). Compound 1 comprised three identical Keggin-like {Ru1.83W10.17} building blocks, leading to the formation of rare {Ru5.5W30.5} trimeric assembly stabilized by a capping pyramidal selenite group; it represents the first example of inorganic ruthenium-containing polyoxometalates based on isopolytungstates. Cyclic voltammetry results revealed that compound 1 also showed electrochemical catalytic activity towards the nitrite oxidation reaction in an aqueous solution.