Influence of surface chemical properties of nanocrystalline CeO2 on phosphate adsorption and methyl-paraoxon decomposition
Jakub Ederer, Ádám Novák, Pavel Janoš, Martin Šťastný, Jiří Henych, Matouš Bárta, Petr Ryšánek, Jakub Tolasz
Abstract
Nanocrystalline cerium oxide (CeO2) was used as an effective catalytic and adsorption material for the safe removal of selected phosphorus compounds. Several CeO2 samples were prepared by a simple coprecipitation method with subsequent annealing at temperatures between 400–600 °C, and their sorption ability for inorganic phosphates was studied together with their ability to decompose the organophosphorus compound - paraoxon methyl (PO) - with the goal to find the relations between the sorption and catalytic activity of the prepared materials. It was found that a complex set of physical and chemical characteristics (surface area, crystallite size, pore volume/size, the number of surface hydroxyl groups) plays a crucial role in the governing of adsorption ability and catalytic activity. From the dependence of some characteristics (i.e., the number of surface hydroxyl groups, BET surface area, crystallite size) on the annealing temperature and their mutual correlations, the model describing the degradation of organophosphate compounds on the surface of cerium oxide was deduced.