Andrey S. Bazhenov

DFT Prediction of Enhanced Reducibility of Monoclinic Zirconia upon Rhodium Deposition

Oxides are an important class of materials and are widely used, for example, as supports in heterogeneous catalysis. In a number of industrial catalytic processes, oxide supports actively participate in chemical transformations by releasing lattice oxygen anions. While this is intuitively understood for reducible oxides, the reducibility of irreducible oxides may be modified via nanoengineering or upon inclusion of foreign species. Our calculations predict that the ability of irreducible monoclinic zirconia to release oxygen improves substantially upon deposition of rhodium. Through a comprehensive screening of Rh/ZrO2 with different size of the rhodium species, we find that a Rh adatom and a Rh4 nanocluster have the largest impact on the reducibility of zirconia. With increasing size the effect of rhodium decays. Our findings demonstrate that the phenomenon of enhanced reducibility of irreducible oxides in the presence of metals should be considered when interpreting experimental and computational results, as reactions that involve release of oxygen from an oxide support might be possible for irreducible oxides.

Understanding Structure and Stability of Monoclinic Zirconia Surfaces from First-Principles Calculations

Under the water-rich pre-treatment and/or reaction conditions, structure and chemistry of the monoclinic zirconia surfaces are strongly influenced by oxygen vacancies and incorporated water. Here, we report a combined first-principles and atomistic thermodynamics study on the structure and stability of selected surfaces of the monoclinic zirconia. Our results indicate that among the studied surfaces, the most stable (

Modeling the Stabilization of Surface Defects by Donors in Ziegler–Natta Catalyst Support

{\overline{1}}11

Stabilization of magnesium dichloride surface defects by mono- and bidentate donors

1¯11) surface is the least vulnerable towards oxygen vacancies in contrast to the less stable (011) and (

A computational study of adhesion between rubber and metal sulfides at rubber–brass interface

{\overline{1}}01

Alkylation of titanium tetrachloride on magnesium dichloride in the presence of Lewis bases

1¯01) surfaces, where formation of oxygen vacancies is energetically more favorable. Furthermore, we present a vigorous, systematic screening of water incorporation onto the studied surfaces. We observe that the greatest stabilization of the surfaces is achieved when a part of the adsorbed water molecules is dissociated. Nevertheless, the importance of water dissociation for achieving the greatest stabilization is high for the less stable (011) and (