prs rt abs end Keywords Mixed transition metal oxides
The morphology was characterized by the scanning AZD8055 microscopy (JSM-6610LV, JEOL) and the transmission electron microscopy (JEM-2100F, JEOL). The pore structure of the samples was determined by the N2 adsorption/desorption isotherm at 77 K (TriStar II 3020, Micromeritics) after they were degassed at 200 °C for 3 h. The specific surface area (SBET) and the pore size distribution (PSD) were analyzed by the Brunauer-Emmett-Teller (BET) method in the relative pressure range of 0.05-0.3 and the non-local density functional theory (NLDFT) from the adsorption branch of the isotherm, respectively. The mesopore volume (Vmeso) of the samples was calculated from the BJH method. The total pore volume (Vt) was estimated from the volume of nitrogen adsorbed at a first law of thermodynamics (conservation) relative pressure P/P0 of 0.995. The micropore volume (Vmicro) of the samples was evaluated by the t-plot method. The surface functionalities and composition were determined by X-ray photoelectron spectroscopy (K-Alpha 1063, Thermo Fisher Scientific) and combustion elemental analysis under Ar (Vario EL, Elementar Analysensysteme GmbH).