Here, we present a study of the development of the micro- and mesoporosity of a CeZrYLaO oxygen storage material upon treatment at temperatures up to 1050 °C. The investigated powder, obtained from nitrate-based metal oxide precursors in a specially developed hydrothermal synthesis, is highly crystalline, features a high surface area and does not show phase segregation at high temperatures. By employing an advanced methodology, consisting of state-of-the-art argon physisorption, thermogravimetric analysis coupled with mass spectrometry (TG-MS) and X-ray powder diffraction (XRD) along with Raman spectroscopy, we correlate the stability of the mesopore system to the presence of surface-bound nitrate groups introduced during synthesis, which prevent sintering up to a temperature of 600 °C.
View Article and Find Full Text PDFMixed ionic and electronic conductors represent a technologically relevant materials system for electrochemical device applications in the field of energy storage and conversion. Here, we report about the design of mixed-conducting nanocomposites by facile surface modification using atomic layer deposition (ALD). ALD is the method of choice, as it allows coating of even complex surfaces.
View Article and Find Full Text PDFConversion/alloy active materials, such as ZnO, are one of the most promising candidates to replace graphite anodes in lithium-ion batteries. Besides a high specific capacity ( = 987 mAh g), ZnO offers a high lithium-ion diffusion and fast reaction kinetics, leading to a high-rate capability, which is required for the intended fast charging of battery electric vehicles. However, lithium-ion storage in ZnO is accompanied by the formation of lithium-rich solid electrolyte interphase (SEI) layers, immense volume expansion, and a large voltage hysteresis.
View Article and Find Full Text PDFPorous carrier materials functionalized with organocatalysts offer substantial advantages compared to homogeneous catalysts, e.g., easy separation of the catalyst, scalability, and an improved implementation in continuous operations.
View Article and Find Full Text PDFThe formation of CeO colloidal particles upon heating an aqueous solution of (NH)Ce(NO) to 100 °C was investigated by time-resolved in situ SAXS analysis using synchrotron radiation, providing absolute intensity data. In particular, the experiments were performed by applying different temperatures between room temperature and 100 °C as well as under variation of the ionic strength and concentration. Using validated SAXS evaluation tools ( and software), the analyses revealed the presence of two types of particle populations possessing average dimensions of ca.
View Article and Find Full Text PDFBy using an evaporation-induced self-assembly (EISA) process, mesoporous metal oxide thin films are prepared via molecular precursors undergoing a sol-gel transition or by using nanoparticle dispersions as the starting materials. Both methods are employed together with PIB--PEO as the structure-directing agent to produce porous TiO and ZrO thin films with spherical mesopores of around 14 nm in diameter. These nanoparticle- and sol-gel-derived films were investigated in terms of the intrinsic in-plane stress development during the heat treatment up to 500 °C to evaluate the impact of solvent evaporation, template decomposition and crystallization on the mechanical state of the film.
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