Water dissociation in CNT-supported IrO₂ nanoparticles

Quantum chemical modeling of iridium oxide nanoparticles—(IrO 2 ) n , n = 1 , 2 , 3 —adsorbed on (5, 5) carbon nanotubes (CNTs) is presented. Energetic, geometric, and electronic aspects have been analyzed in depth to understand the main features of the nanoparticles in the gas phase and the adsorption process involved. Covalent Ir-C bonding resulted from the interaction of the (IrO 2 ) 1 and (IrO 2 ) 3 particles with the CNT. To evaluate the performance of the material, the dissociation of water into H ( a d s ) and OH ( a d s ) has been investigated. Our results revealed that the intrinsic charge polarization of the iridium oxide clusters favors the water dissociation process, with low activation energies. Moreover, the nanoparticles remain stable and maintain covalent interactions with the CNT surface during the water dissociation process.