Designing well-defined magnetic nanomaterials is crucial for various applications, and it demands a comprehensive understanding of their magnetic properties at the microscopic level. In this study, we investigate the contributions to the total anisotropy of Mn/Co mixed spinel nanoparticles. By employing neutron measurements sensitive to the spatially resolved surface anisotropy with sub-Å space resolution, we reveal an additional contribution to the anisotropy constant arising from shape anisotropy and interparticle interactions. Our findings shed light on the intricate interplay among chemical composition, microstructure, morphology, and surface effects, providing valuable insights for the design of advanced magnetic nanomaterials for AC biomedical applications, such as cancer treatment by magnetic fluid hyperthermia.

In this work, non-ordered and ordered CeO₂-based catalysts are proposed for CO₂ conversion to dimethyl carbonate (DMC). Particularly, non-ordered mesoporous CeO₂, consisting of small nanoparticles of about 8 nm, is compared with two highly porous (635–722 m²/g) ordered CeO₂@SBA-15 nanocomposites obtained by two different impregnation strategies (a two-solvent impregnation method (TS) and a self-combustion (SC) method), with a final CeO₂ loading of 10 wt%. Rietveld analyses on XRD data combined with TEM imaging evidence the influence of the impregnation strategy on the dispersion of the active phase as follows: nanoparticles of 8 nm for the TS composite vs. 3 nm for the SC composite. The catalytic results show comparable activities for the mesoporous ceria and the CeO₂@SBA-15_SC nanocomposite, while a lower DMC yield is found for the CeO₂@SBA-15_TS nanocomposite. This finding can presumably be ascribed to a partial obstruction of the pores by the CeO₂ nanoparticles in the case of the TS composite, leading to a reduced accessibility of the active phase. On the other hand, in the case of the SC composite, where the CeO₂ particle size is much lower than the pore size, there is an improved accessibility of the active phase to the molecules of the reactants.

Solution combustion (SC) remains among the most promising synthetic strategies for the production of crystalline nanopowders from an aqueous medium, due to its easiness, time and cost‐effectiveness, scalability and eco‐friendliness. In this work, this method was selected to obtain anisometric ceria‐based nanoparticles applied as catalysts for the direct synthesis of dimethyl carbonate. The catalytic performances were studied for the ceria and Fe‐doped ceria from SC (CeO ₂ ‐SC, Ce _0.9 Fe _0.1 O ₂ ‐SC) in comparison with the ceria nanorods (CeO ₂ ‐HT, Ce _0.9 Fe _0.1 O ₂ ‐HT) obtained by hydrothermal (HT) method, one of the most studied systems in the literature. Indeed, the ceria nanoparticles obtained by SC were found to be highly crystalline, platelet‐shaped, arranged in a mosaic‐like assembly and with smaller crystallite size (≈6 nm vs . ≈17 nm) and higher surface area (80 m ² g ⁻¹ vs . 26 m ² g ⁻¹ ) for the undoped sample with respect to the Fe‐doped counterpart. Although all samples exhibit an anisometric morphology that should favor the exposition of specific crystalline planes, HT‐samples showed better performances due to higher oxygen vacancies concentration and lower amount of strong basic and acid sites.

A synthesis strategy combining an impregnation approach with a self-combustion process to develop Ni-based catalysts (5–15 wt% of Ni) supported on mesoporous CeO2 is proposed. This strategy favors an intimate Ni–CeO2 coupling enabling a fine NiO dispersion in form of ultrasmall particles/clusters on CeO2. Comprehensive characterization, including XRD, Raman, N2-physisorption, HRTEM, STEM-EDXS/EELS, H2-TPR, CO2-TPD, and H2-TPD, revealed a strong metal–support interaction and promotion of oxygen vacancy formation. CO2 methanation testing under atmospheric pressure demonstrated high CO2 conversion and near-complete CH4 selectivity. At lower reaction temperatures, CO₂ conversion increased with Ni loading, which can be reasonably attributed to the higher concentration of oxygen vacancies. However, above 325 °C, the catalyst with the lowest Ni content exhibited performances comparable to the other samples, likely due to its very high Ni dispersion. Notably, a critical comparison with state-of-the-art systems, despite differences in operating conditions, highlighted the outstanding performance of the catalysts, particularly in terms of methane productivity (256-486 ), CO2 conversion (68-85 mol%) and CH4 selectivity (close to 100%) under mild conditions. The results place the obtained Ni–CeO2 catalysts among the most effective systems reported to date for CO2 methanation with strong potential for integration in sustainable catalytic technologies.