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 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.

Electronic structure of NdO via slow photoelectron velocity-map imaging spectroscopy of NdO¯

“…The proposed term energy of 2350 cm -1 for the (2)4.5 excited state of NdO¯ is supported by our CASSCF simulations, which predict such a level to reside 2724 cm -1 above the ground state. Further, the presence of anions trapped in low-lying excited states has been observed previously in cryo-SEVI studies, [69][70][71][72] though it is notable that the (2)4.5 state of NdO¯ lies considerably above the anion ground state, and above 5 other excited states that are not present in the cryo-SEVI spectrum in Fig. 1B.…”

Spectroscopy of Radicals, Clusters, and Transition States Using Slow Electron Velocity-Map Imaging of Cryogenically Cooled Anions

“…Peak assignments are discussed in the main text. Reproduced with permission from ref . Copyright 2020 American Institute of Physics.…”

Spectroscopy of radicals, clusters, and transition states using slow electron velocity-map imaging of cryogenically cooled anions

“…While the TiO(OH)2 0/ ˉ complexes are planar, the ZrO(OH)2 0/ ˉ complexes are not, with dihedral angles of 23.0 and 29.2, respectively. 48 This non-planarity has a significant effect on the cryo-SEVI spectra as discussed below.…”

“…94 The corresponding spectra of TiO2ˉH2O and ZrO2ˉH2O shown in Figures 4 and 5, respectively, are considerably more complex and differ substantially from one another. [48][49] The overview TiO2ˉH2O spectrum (in blue) has a pronounced progression (A1, A3, A7, A11) with a characteristic peak spacing of 678 cm -1 , along with multiple smaller features. Higher resolution spectra (in black) reveal an additional series of peaks B1-B11 that are not evident in the overview spectrum.…”

“…Cryo-SEVI experiments in our laboratory and elsewhere were reviewed in 2018. 46 This perspective focuses on results obtained since then, with particular focus on the cryo-SEVI spectra of NO3¯, 47 the hydrated metal oxide clusters TiO3H2¯ and ZrO2H2¯, [48][49] and the transition state precursor anions H2CC¯ and F¯(NH3). 13,50 In addition, a new experimental direction is discussed in which anions are pre-excited with an infrared (IR) laser prior to photodetachment.…”