Unveiling the Coexistence of Cis and Trans Isomers in the Hydrolysis of ZrO2: A Coupled DFT and High-Resolution Photoelectron Spectroscopy Study

Abstract

High-resolution anion photoelectron spectroscopy of the ZrO<sub>3</sub>H<sub>2</sub><sup>-</sup> and ZrO<sub>3</sub>D<sub>2</sub><sup>-</sup> anions and complementary electronic structure calculations are used to investigate the reaction between zirconium dioxide and a single water molecule, ZrO<sub>2</sub><sup>0/-</sup> + H<sub>2</sub>O. Experimental spectra of ZrO<sub>3</sub>H<sub>2</sub><sup>-</sup> and ZrO<sub>3</sub>D<sub>2</sub><sup>-</sup> were obtained using slow photoelectron velocity-map imaging (cryo-SEVI), 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 \textit{cis}-- and \textit{trans}--dihydroxide structures are required to fully reproduce the experimental spectrum. Additionally, it was found that water-splitting is stabilized more by ZrO<sub>2</sub> than TiO<sub>2</sub>, suggesting Zr-based catalysts are more reactive toward hydrolysis.