Interaction of water with titania and zirconia surfaces

Review: monoclinic zirconia, its surface sites and their interaction with carbon monoxide

“…Dissociative adsorption of water on monoclinic zirconia is exothermic, occurring already at room temperature 31,69 . Therefore the surfaces of zirconia are hydroxylated under ambient and in most reactive atmospheres.…”

“…Hydroxyl densities can be estimated based on the amount of water removed from zirconia 34 , water adsorbed on zirconia 27,69 , or on quantification via 1 H MAS NMR 68 , and these estimates are presented in Table 3. In the table, the scaled values represent OH density regardless whether it has been measured directly or by water adsorption (each water molecule is assumed to form two surface hydroxyls).…”

“…This is in agreement with the values measured for powder zirconias (1.0 − 1.6 m 2 /g) 32 giving a range from −110 kJ/mol to −170 kJ/mol. Theoretical adsorption energy values typically range from −80 kJ/mol to −190 kJ/mol on (001), (111), (111), and (101) 67,69,85 . We have recently reported dissociative adsorption energies for the first adsorbing water molecule ranging from −106 .…”

“…OD groups, known as deuteroxyls, have been investigated by many groups 19,21,24,42,44,56,59,61,87 while oxygen-labeling studies are more scarce 66,69,81 .…”

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

“…A few research groups have reported water adsorption on the most abundant low-index m-ZrO 2 surfaces, such as (111), (101), and (111), to be dissociative at low surface coverage. [15,19] Piskorz et al have performed computational studies on surface hydration and equilibria of m-and t-ZrO 2 . [30,31] The authors have reported significant stabilization of the (111), (111), (011), and (001) surfaces of m-ZrO 2 upon adsorption of water.…”