Hydrogenated ceria nanoparticles for high-efficiency silicate adsorption

The enriched Ce3+ ions were confirmed on the surface of hydrogenated ceria nanoparticles which play a key role as active sites in various chemical reactions including silicate adsorption.

In-situ modified the surface of Pt-doped perovskite catalyst for soot oxidation

In-situ modification is studied in this work on LaCo_1-xPt_xO₃ for soot oxidation. A series of perovskite catalysts LaCo_1-xPt_xO₃ (by sol-gel method) are modified with 30% H₂O₂. XRD, TEM, SEM, BET, XPS, Raman, in-situ DRIFTS, H₂-TPR and TGA are used to investigate physicochemical properties of catalysts. TGA results show that all doped catalysts have a lower temperature of soot conversion, especially LaCo_0.94Pt_0.06O₃ (T₅₀ = 437 °C). The T₅₀ of the catalyst with modification by H₂O₂ solution decreases at least 20 °C compared with the doped catalysts. A highly symmetrical structure and an obvious amorphous layer about 3-5 nm are observed in the modified catalysts. According to the XPS study, the symmetrical structure benefits to the movement of oxygen vacancy thus catalyst captures more adsorbed oxygen (about 95%). And the amorphous surface could adsorb more oxygen species. In addition, all catalysts show excellent aging resistance performance. The reaction mechanism of catalyst for soot oxidation is presented in the end.

Effects of hydrogen peroxide co-precipitation and inert N2 atmosphere calcination on CeZrLaNd mixed oxides and the catalytic performance used on Pd supported three-way catalysts

The unique reversible oxygen storage and release capacity of cerium zirconium mixed oxides makes them ideal washcoat materials of automotive three-way catalysts (TWC). In this work, cerium zirconium mixed oxides of Ce_0.15Zr_0.79La_0.02Nd_0.04O₂ were prepared via a co-precipitation method. The effects of hydrogen peroxide co-precipitation and inert N₂ atmosphere calcination on the structure and properties of cerium zirconium mixed oxides were investigated systematically by Brunauer-Emmett-Teller surface area measurements, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, hydrogen temperature-programmed reduction, oxygen storage capacity (OSC), Raman spectroscopy, and X-ray photoelectron spectroscopy. Additionally, the catalytic performance of palladium supported catalysts was studied. Results show that hydrogen peroxide co-precipitation promotes the dispersion of cerium zirconium particles and enhances crystal grain growth, resulting in good thermal stability of the obtained cerium zirconium mixed oxides. Inert N₂ atmosphere calcination also enhances the dispersion of particles, results in smaller and finer crystal grains, enriches pore channels, and significantly improves the surface area, pore volume and OSC, with an OSC of 424.57 μmolO₂ g^-1, which is a 13.37% increment compared with the common sample. The benefits of hydrogen peroxide co-precipitation and inert N₂ atmosphere calcination endow the Pd supported catalysts of cerium zirconium mixed oxides with good three-way catalytic performance.

Ab initio insights into the structural, energetic, electronic, and stability properties of mixed CenZr15−nO30 nanoclusters

In this work, we report a DFT investigation combined with Spearman correlation analysis of the energetic, structural and electronic properties of mixed Ce_nZr_15−nO₃₀ nanoclusters as a function of the composition (n = 0, 1,…,14, 15).

Superior catalytic performance of a CoOx/Sn–CeO2 hybrid material for catalytic diesel soot oxidation

A Co₃O₄/Sn–CeO₂ hybrid catalyst exhibited superior soot oxidation activity due to the existence of synergism among the multivalent cations and the stepped surface of the hybrid catalyst.