Unveiling the coexistence of cis- and trans-isomers in the hydrolysis of ZrO2: A coupled DFT and high-resolution photoelectron spectroscopy study.

High-resolution anion photoelectron spectroscopy of the ZrO3H2− and ZrO3D2− anions and complementary electronic structure calculations are used to investigate the reaction between zirconium dioxide and a single water molecule, ZrO20/− + H2O. Experimental spectra of ZrO3H2− and ZrO3D2− were obtained using slow photoelectron velocity-map imaging of cryogenically cooled anions, revealing the presence of two dissociative adduct conformers and yielding insight into the vibronic structure of the corresponding neutral species. Franck–Condon simulations for both the cis- and trans-dihydroxide structures are required to fully reproduce the experimental spectrum. Additionally, it was found that water-splitting is stabilized more by ZrO2 than TiO2, suggesting Zr-based catalysts are more reactive toward hydrolysis.