Methyl orange degradation enhanced by hydrogen spillover onto platinum nanocatalyst surface

Following a thermal reduction method, platinum nanoparticles were synthesized and stabilized by polyvinylpyrrolidone. The colloidal platinum nanoparticles were stable for more than 3 months. The micrograph analysis unveiled that the colloidal platinum nanoparticles were well dispersed with an average size of 2.53 nm. The sol–gel‐based inverse micelle strategy was applied to synthesize mesoporous iron oxide material. The colloidal platinum nanoparticles were deposited on mesoporous iron oxide through the capillary inclusion method. The small‐angle X‐ray scattering analysis indicated that the dimension of platinum nanoparticles deposited on mesoporous iron oxide (Pt‐Fe₂O₃) was 2.64 nm. X‐ray photoelectron spectroscopy (XPS) data showed that the binding energy on Pt‐Fe₂O₃ surface decreased owing to mesoporous support–nanoparticle interaction. Both colloidal and deposited platinum nanocatalysts improved the degradation of methyl orange under reduction conditions. The activation energy on the deposited platinum nanocatalyst interface (2.66 kJ mol^?1) was significantly lowered compared with the one on the colloidal platinum nanocatalyst interface (40.63 ± 0.53 kJ mol^?1).     

Cover Feature: Oxidation of Benzyl Alcohol Using Cobalt Oxide Supported Inside and Outside Hollow Carbon Spheres (ChemistryOpen 6/2021)

The Cover Feature shows the cobalt oxide nanoparticles supported both inside and outside hollow carbon spheres (HCSs), which serve as a catalyst for benzyl alcohol oxidation. A metal oxidation step prior to the reaction enhanced the catalytic activity of benzyl alcohol which was used as a model reaction for the catalysts. Both catalysts showed similar activity and selectivity (to benzaldehyde) whether placed inside or outside the HCSs (70% selectivity at 50% conversion). No poisoning was observed due to product build up in the HCSs. More information can be found in the Full Paper by Pumza Mente et al.     

Morphology and properties of nanostructured materials based on polypropylene/poly(butylene succinate) blend and organoclay

Nanostructured materials based on organically modified montmorillonite (OMMT) and polypropylene (PP)/poly(butylene succinate) (PBS) blend were prepared via melt-mixing of PP, PBS, and OMMT in a batch mixer. The weight ratio of PP and PBS was 70:30, and the OMMT loading varied from 0.5 to 5 wt%. The surface morphologies of unmodified and OMMT-modified blend were studied by field-emission scanning electron microscopy. Results showed that the particle size of the dispersed PBS phase was significantly reduced with the addition of a small amount of OMMT (1.5 wt%). Upon the addition of 5 wt% of OMMT, the domain size of the dispersed PBS phase changed significantly from the unmodified blend, and a homogeneous dispersion of very fine particles of PBS was observed. The degree of dispersion of silicate layers in the blend matrix was characterized by X-ray diffraction and transmission electron microscopy. The improved adhesion between the phases and the fine morphology of the dispersed phase contributed to the significant improvement in the properties and thermal stability of the final nanocomposite materials. On the basis of these results, we describe a general understanding of how the morphology is related to the final properties of OMMT-incorporated PP/PBS blend.     

Systematic trends in boron icosahedral structured materials

Boron materials exist in many different structures with an important similarity that they all contain connected B₁₂ icosahedra. Various structures that hold potential for super-hard material properties are examined using ab initio computational techniques. Systematic trends are established. The charge density between all B-B bonds in each structure that are examined and it is suggested that hardness of the material may, in part, relate to the average charge density between the boron bonds. Atoms connecting the B icosahedra donating charge that enhance the strength of the B-B bonds.     

Oxidation of Benzyl Alcohol Using Cobalt Oxide Supported Inside and Outside Hollow Carbon Spheres

Cobalt oxide nanoparticles (6 nm) supported both inside and outside of hollow carbon spheres (HCSs) were synthesized by using two different polymer templates. The oxidation of benzyl alcohol was used as a model reaction to evaluate the catalysts. PXRD studies indicated that the Co oxidation state varied for the different catalysts due to reduction of the Co by the carbon, and a metal oxidation step prior to the benzyl alcohol oxidation enhanced the catalytic activity. The metal loading influenced the catalytic efficiency, and the activity decreased with increasing metal loading, possibly due to pore filling effects. The catalysts showed similar activity and selectivity (to benzaldehyde) whether placed inside or outside the HCS (63 % selectivity at 50 % conversion). No poisoning was observed due to product build up in the HCS.