In addition, measures taken to obtain outstanding selectivity for F-T synthesis and C C bond hydrogenation reactions are also presented. In this review, design strategies for core/yolk shell nanocatalysts to attain high stability in energy related applications at high temperatures such as hydrocarbon reforming reactions for syngas production and high temperature fuel cells such as SOFC and MCFC are summarized and exemplified with the advancements made in the recent three years. Structural design of nanocatalysts to form core/yolk shell structure has been proven to be the most effective method to enhance their catalytic stability. Despite the prominent feature of high catalytic activity, nanocatalysts are prone to sintering. All these aspects are directly influenced by the configuration of samples.read more read lessĪbstract: In recent decades, increasing interests have been put on improving the stability and selectivity of nanocatalysts for clean energy production due to the decrease of fossil fuels. Together with BET surface area measurements, direct assessment of the density of photocatalytic sites probed by electron paramagnetic resonance measurements was used to provide insight into the enhanced photocatalytic activity of CSNs, which is also understood as a consequence of Rayleigh scattering, relative enhancement of the adsorption of organic molecules on the photocatalyst surface and increased optical path inside the particles. An enhanced photoactivity and good recyclability of CSNs was demonstrated compared to unsupported TiO2. The configuration leads to efficient light harvesting by increasing the optical path inside the particles. Both experimental data and theoretical simulations showed that due to the size of the complete particle the general optical response of the system is regulated by Rayleigh scattering, exhibiting a red-shift of the extinction spectra as shell-thickness increases. The resulting CSNs were characterized by scanning electron microscopy, transmission electron microscopy, energy dispersive spectroscopy, x-ray photoelectron spectroscopy, X-ray diffraction, vibrational spectroscopy, zeta-potential measurements, BET surface area and electron paramagnetic resonance measurements. The amorphous TiO2 shell was crystallized into anatase using a low temperature (105 ☌) hydrothermal treatment. For this purpose, synthesis of highly dispersed anatase nanocrystals (∼5 nm) of high surface area was carried out by supporting these nanocrystals on silica sub-micron spheres in the form of a porous shell of controlled thickness (10–30 nm). Here we report a very facile and reproducible method for the synthesis of CSNs with a control of particle morphology, crystallinity and phase selectivity, and provide important insight into the effect of configuration on the photocatalytic and optical properties of CSNs. Thus, development of facile, reproducible and effective methods for the synthesis of CSNs and a fundamental understanding of their improved properties, derived from combination of different core and shell materials, is of great importance. Abstract: nanoparticles (CSNs) have recently attracted great attention due to their unique and tunable optical and photocatalytic properties and higher dispersion of the supported TiO2.
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