Palladium nanoparticles of similar size were deposited on different supports, layers of carbon materials (with and without nitrogen doping) on the surface of a MCF (mesocellular foam) silica.

One-dimensional (1D) core-sheath nanofibers, platinum (Pt)-loaded ceria (CeO₂) sheath on mesoporous silica (SiO₂) core were fabricated, characterized, and used as catalysts for the reverse water gas shift reaction (RWGS). CeO₂ nanofibers (NFs) were first prepared by electrospinning (ES), and then Pt nanoparticles were loaded on the CeO₂ NFs using two different deposition methods: wet impregnation and solvothermal. A mesoporous SiO₂ sheath layer was then deposited by sol-gel process. The phase composition, structural, and morphological properties of synthesized materials were investigated by scanning electron microscope (SEM), scanning transmission electron microscopy (STEM), X-ray diffraction (XRD), nitrogen adsorption/desorption method, X-ray photoelectron spectroscopy (XPS), inductively coupled plasma—optical emission spectrometry (ICP-OES) analysis, and CO₂ temperature programmed desorption (CO₂-TPD). The results of these characterization techniques revealed that the core-sheath NFs with a core diameter between 100 and 300 nm and a sheath thickness of about 40–100 nm with a Pt loading of around 0.5 wt.% were successfully obtained. The impregnated catalyst, Pt-CeO₂ NF@mesoporous SiO₂, showed the best catalytic performance with a CO₂ conversion of 8.9% at 350 °C, as compared to the sample prepared by the Solvothermal method. More than 99% selectivity of CO was achieved for all core-sheath NF-catalysts.

The selective oxidation of alcohols aiming at the formation of aldehydes and esters is an essential reaction for the fine chemical industry. However, the classical processes to obtain aldehydes present many limitations, such as waste generation, low selectivity, or high cost. Herein, we address the production and characterization of porous N-doped carbon derived from chitosan. This solid was used as the support for earth-abundant transition metal oxides such as Fe₂O₃, CoO, NiO, or CuO nanoparticles. These materials were used as catalysts for the oxidation of primary alcohols by activating peroxydisulfate or peroxymonosulfate. Quenching tests were performed and a considerable contribution of a non-radical oxidation process was indicated.