Influence of the monoclinic and tetragonal zirconia phases on the water gas shift reaction. A theoretical study

We present a theoretical study of the water gas shift reaction taking place on zirconia surfaces modeled by monoclinic and tetragonal clusters. In order to understand the charge transfer between the active species, in this work we analyze the influence of the geometry of monoclinic and tetragonal zirconia using reactivity descriptors such as electronic che − mical potential (μ), charge transfer (\( \left| {\varDelta N} \right| \)) and molecular hardness (η). We have found that the most preferred surface is tetragonal zirconia (tZrO 2) indicating also that low charge transfer systems will generate less stable intermediates, that will allow to facilitate desorption process.