Effect of synthesis conditions on the porous texture of activated carbons obtained from Tara Rubber by FeCl3 activation

This paper presents the results of an unique analysis of the influence of the mass ratio of activator FeCl3 to precursor and the temperature of the activation process on the formation of the porous structure of activated carbons obtained from Tara Rubber by FeCl3 activation. The study used the new numerical clustering based adsorption analysis method and the quenched solid density functional theory, taking into account, among other things, the heterogeneity of the analysed surface which is a new approach rarely used in the analysis of the porous structure of adsorbents. On the basis of the calculation results, it was concluded that the activated carbon with the most developed porous texture was obtained at a mass ratio (FeCl3:Tara Rubber) of 2, at an activation process temperature of 800 °C. This activated carbon is also characterised by the lowest degree of surface heterogeneity and at the same time, however, the widest range of micropores compared to activated carbons obtained at other mass ratios. The analyses carried out further demonstrated the valuable and complementary information obtained from the structure analysis methods and their high utility in practical applications, especially in the development of new industrial technologies for the production of adsorbents and the selection of optimal conditions for their production.

Oxidation of Benzyl Alcohol Compounds in the Presence of Carbon Hybrid Supported Platinum Nanoparticles (Pt@CHs) in Oxygen Atmosphere

A novel catalyst which carbon hybrid supported platinum nanoparticles were synthesized by our group for the oxidation of benzyl alcohol derivatives. In this study, this catalyst was utilized for the oxidation of benzyl alcohol derivatives to benzaldehyde compounds in aqueous toluene at 80 °C. The benzaldehyde derivatives were synthesized in high yields and mild conditions in the presence of the catalyst by the developed method. Additionally, the prepared nanoparticles have been characterized by Transmission Electron Microscopy (TEM), the high-resolution electron micrograph (HR-TEM), X-ray Photoelectron Spectroscopy (XPS), and X-ray Diffraction (XRD). The mean particle size of the nanoparticles determined by the XRD technique was found to be 2.83 nm in parallel with TEM analysis. TEM analysis also indicated that the Pt nanoparticles were evenly dispersed on the support material. Finally, the Pt@CHs catalyst was shown also stable and reusable for the oxidation reaction, providing ≤95% conversion after its 3rd consecutive use in the oxidation reaction of various compounds.

Particle Size-Controlled Growth of Carbon-Supported Platinum Nanoparticles (Pt/C) through Water-Assisted Polyol Synthesis

A water-assisted control of Pt nanoparticle size during a surfactant-free, microwave-assisted polyol synthesis of the carbon-supported platinum nanoparticles (Pt/C) in a mixture of ethylene glycol and water using (NH₄)₂PtCl₆ as the Pt precursor is demonstrated. The particle size was tuned between ∼2 and ∼6 nm by varying either the H₂O volume percent or the Pt precursor concentration during synthesis. The electrochemical surface area (ECSA) and the oxygen-reduction reaction activity obtained for the Pt/C electrocatalyst show a catalytic performance competitive to that of the state-of-the-art commercial Pt/C electrocatalysts used for polymer electrolyte membrane fuel cell electrodes (ECSA: ∼70 m²/g; half-wave potential for oxygen reduction reaction: 0.83 V vs reversible hydrogen electrode). The synthesized Pt/C electrocatalysts show durability equivalent to or better than that of the commercial Pt/C. The durability was found to improve with increasing particle size, with the ECSA loss values being ∼70 and ∼55% for the particle sizes of 2.1 and 4.3 nm, respectively. The study may be used as a route to synthesize Pt/C electrocatalysts from a convenient and economic Pt precursor (NH₄)₂PtCl₆ and avoiding the use of alkaline media.

Synthesis of triphenylamines via ligand-free selective ring-opening of benzoxazoles or benzothiazoles under superparamagnetic nanoparticle catalysis

Synthesis of triphenylamines via ligand-free selective ring-opening of benzoxazoles or benzothiazoles with aryl halides under CuFe₂O₄ superparamagnetic nanoparticle catalysis.

Controlled synthesis of PVP-based carbon-supported Ru nanoparticles: synthesis approaches, characterization, capping agent removal and catalytic behavior

PVP-capped Ru nanoparticles were synthesized, immobilized on several carbon supports and tested in galactose hydrogenation.