Highly selective CC bond hydrogenation in α,β-unsaturated ketones catalyzed by hectorite-supported ruthenium nanoparticles

Ruthenium Nanoparticles Intercalated in Montmorillonite (nano-Ru@MMT) Is Highly Efficient Catalyst for the Selective Hydrogenation of 2-Furaldehyde in Benign Aqueous Medium

Chemoselective hydrogenation of 2-furaldehyde to furfuryl alcohol using green solvents is an important research area to get eco-friendly fuels and fine chemicals. Herein, we report ruthenium nanoparticles (~1.8 nm) intercalated in montmorillonite as an efficient catalytic system, which can selectively hydrogenate 2-furaldehyde in a benign aqueous medium. The complete conversion was observed at 40 °C with 1 MPa H2, the selectivity of furfuryl alcohol being >99%, and turnover number 1165. After a catalytic run, the montmorillonite-supported ruthenium nanoparticles can be recycled and reused without losing their activity and selectivity.

Direct Transformation of Glycerol to Propanal using Zirconium Phosphate-Supported Bimetallic Catalysts

Selective transformation of glycerol to propanal (PA) provides a feasible route towards the sustainable synthesis of high value-added chemicals. In this work, zirconium phosphate (ZrP) was studied as support and Ru and Co as metal sites for glycerol hydrogenolysis in a continuous-flow reactor. It was found that ZrP-supported Co-O species had a moderate selectivity to PA (49.5 %) in glycerol hydrogenolysis. Notably, once Ru species were doped into CoO/ZrP, the resulting catalyst exhibited not only an outstanding catalytic performance for glycerol hydrogenolysis to PA (a selectivity of 80.2 % at full conversion), but also a high stability at least a 50 h long-term performance. The spent catalyst could be regenerated by calcining in air to remove carbonaceous deposits. Characterization indicated that the acid sites on ZrP played a very critical role in the dehydration of glycerol into acrolein (AE), that the distribution of Co was uniform, basically consistent with that of Zr, P and Ru, and that an especially close contact between Co-O and Ru species was formed on Ru/CoO/ZrP catalyst. The further activity tests and characterizations confirmed that there was a strong interaction between the dispersed Co-O species and Ru⁰ nanoparticles, which endowed Ru sites with high electronic density. This effect could play a role in facilitating the dissociation of H₂ , and thus in promoting the hydrogenation reaction. Besides, DFT calculations suggested that the Co-O species can adsorb more strongly the C=C bond of the intermediate AE on a highly coordinatively unsaturated Co (Co_cus ) site and thus lead to preferential hydrogenation at the C=C bond of AE to PA.

Highly Efficient Liquid-Phase Hydrogenation of Naringin Using a Recyclable Pd/C Catalyst

A highly efficient liquid-phase hydrogenation reaction using a recyclable palladium on carbon (Pd/C) catalyst has been used for the transformation of naringin to its corresponding dihydrochalcone. The effects of various solvents on the hydrogenation process were studied, with water being identified as the optimal solvent. The analysis also revealed that sodium hydroxide (NaOH) can accumulate on the surface of the Pd/C catalyst in alcoholic solvents, leading to its inactivation. The higher solubility of NaOH in water implies that it remains in solution and does not accumulate on the Pd/C catalyst surface, ensuring the catalytic activity and stability.

New biobased tetrabutylphosphonium ionic liquids: synthesis, characterization and use as a solvent or co-solvent for mild and greener Pd-catalyzed hydrogenation processes

Phosphonium-based ionic liquids with natural organic derived anions were easily prepared and showed good performance and recyclability in Pd-catalyzed hydrogenation processes at room temperature under atmospheric H₂ pressure.

The production of bio-jet fuel from Botryococcus braunii liquid over a Ru/CeO2catalyst

In this study, the conversion fromBotryococcus brauniiliquid to bio-jet fuelviaa Ru/CeO₂catalyst was conducted.

Highly efficient and chemoselective hydrogenation of α,β-unsaturated carbonyls over Pd/N-doped hierarchically porous carbon

Pd supported on N-doped hierarchically porous carbon was successfully applied in the selective hydrogenation of CC bonds.