We present a detailed study of the interaction between the ZrO2 molecule and H-2 within DFT and CCSD(T) approaches. H-2 activation is followed by cleavage of H-H bond giving OZrH-OH species with hydride and hydroxyl groups. Both direct transfer of H from Zr-H to Zr-OH and a two step process via a Zr(OH)(2) intermediate (in a triplet state) lead to water formation generating ZrO center dot center dot center dot H2O. The hybrid B3LYP or PBE0 functionals with SDD pseudopotential/ basis set on Zr and 6-311++G(2df,2p) basis sets for O, H represent the best compromise between accuracy and computational cost. (C) 2010 Elsevier B. V. All rights reserved.