Study of Ni, Pt, and Ru Catalysts on Wood-based Activated Carbon Supports and their Activity in Furfural Conversion to 2-Methylfuran

High-Loaded Copper-Containing Sol-Gel Catalysts for Furfural Hydroconversion

In this study, the high-loaded copper-containing catalysts modified with Fe and Al were successfully applied for the hydroconversion of furfural to furfuryl alcohol (FA) or 2-methylfuran (2-MF) in a batch reactor. The synthesized catalysts were studied using a set of characterization techniques to find the correlation between their activity and physicochemical properties. Fine Cu-containing particles distributed in an amorphous SiO₂ matrix, which has a high surface area, provide the conversion of furfural to FA or 2-MF under exposure to high pressure of hydrogen. The modification of the mono-copper catalyst with Fe and Al increases its activity and selectivity in the target process. The reaction temperature strongly affects the selectivity of the formed products. At a H₂ pressure of 5.0 MPa, the highest selectivity toward FA (98%) and 2-MF (76%) was achieved in the case of 35Cu13Fe1Al-SiO₂ at the temperature of 100 °C and 250 °C, respectively.

Near-Infrared Femtosecond Laser Ablation of Au-Coated Ni: Effect of Organic Fluids and Water on Crater Morphology, Ablation Efficiency and Hydrodynamic Properties of NiAu Nanoparticles

Scanning electron microscopy (SEM) and profilometry of the crater morphology and ablation efficiency upon femtosecond laser ablation of Au-coated Ni targets in various fluids revealed a pronounced dependence on the ablation medium. For ethanol, a sufficient ablation efficiency was obtained, whereas for 2-butanol a higher efficiency indicated stronger laser-target interaction. Hierarchical features in the crater periphery pointed to asymmetrical energy deposition or a residual effect of the Coulomb-explosion-initiating ablation. Significant beam deviation in 2-butanol caused maximum multiple scattering at the crater bottom. The highest values of microstrain and increased grain size, obtained from Williamson-Hall plots, indicated the superposition of mechanical stress, defect formation and propagation of fatigue cracks in the crater circumference. For n-hexane, deposition of frozen droplets in the outer crater region suggested a femtosecond-laser-induced phase explosion. A maximum ablation depth occurred in water, likely due to its high cooling efficiency. Grazing incidence micro X-ray diffraction (GIXRD) of the used target showed residual carbon and partial surface oxidation. The produced nanoparticle colloids were examined by multiangle dynamic light scattering (DLS), employing larger scattering angles for higher sensitivity toward smaller nanoparticles. The smallest nanoparticles were obtained in 2-butanol and ethanol. In n-hexane, floating carbon flakes originated from femtosecond-laser-induced solvent decomposition.

Hydrogenation of α-Pinene over Platinum Nanoparticles Reduced and Stabilized by Sodium Lignosulfonate

A one-pot clean preparation procedure and catalytic performance of platinum nanoparticles (NPs) reduced and stabilized by sodium lignosulfonate in aqueous solution are reported. No other chemical reagents are needed during the metal reduction and stabilization step, thanks to the active participation of sodium lignosulfonate (SLS). UV-vis, Fourier transform infrared (FT-IR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), 1H NMR, 195Pt NMR, and two-dimensional heteronuclear single-quantum coherence (2D HSQC) NMR studies were thoroughly performed to analyze the formation, particle size, and main lattice planes of NPs, the valence-state changes of the metal, and structural changes of SLS. An ecofriendly selective synthesis of cis-pinane from an abundant renewable natural resource, α-pinene, was developed in the presence of the prepared Pt NP aqueous system. Furthermore, this catalyst system was proved to show easy recovery and stable reusability by five-run tests. The synergistic effect of SLS reduction and stabilization not only avoided the introduction of conventional reducing agents and stabilizers but also made full use of the byproducts of the pulp and paper industry. This proved to be an environmentally friendly method for converting the natural resource α-pinene to cis-pinane.