Relevant articles and documents
Pd, Cu and Bimetallic PdCu NPs Supported on CNTs and Phosphine-Functionalized Silica: One-Pot Preparation, Characterization and Testing in the Semi-Hydrogenation of Alkynes
Sánchez-Resa, Daniel Delgado, Jorge A. Fernández-Martínez, Maria Dolores Didelot, Chloé De Mallmann, Aimery Szeto, Ka? C. Taoufik, Mostafa Claver, Carmen Godard, Cyril
Triphenylphosphine stabilized Pd, Cu and PdCu nanocatalysts supported on carbon nanotubes (CNTs) or phosphorus functionalised silica (P?SiO2) were prepared via a one-pot methodology. The series of P?SiO2 supported catalysts evidenced metal particle sizes of metallic nanoparticles (M-NPs) between 1 and 2.4 nm, smaller than their equivalents on CNTs (2.4–2.6 nm). Such a difference in particle size as a function of the support and the metallic composition indicated the more pronounced mediation of the CNTs support during the formation of the M-NPs when compared to the P?SiO2 support. The series of supported catalysts were tested in the semi-hydrogenation of alkynes providing differences in reactivity which might be correlated with the size and composition of the M-NPs and the nature of corresponding support. The carbon supported catalysts displayed in general higher activities than those supported on silica and the bimetallic catalyst PdCu/CNTs were the most selective for the case of alkyl substituted alkynes. This catalyst could moreover be recycled several times without loss of activity nor selectivity.
Production of Alcohols from Olefins via One-Pot Tandem Hydroformylation-Acetalization-Hydrogenolysis over Bifunctional Catalyst Merging RuIII-P Complex and RuIII Lewis Acid
Wang, Peng Wang, Dong-Liang Liu, Huan Zhao, Xiao-Li Lu, Yong Liu, Ye
A novel three-step tandem hydroformylation-acetalization-hydrogenolysis was first proposed to produce alcohols (derivatives) from olefins, and the developed unique Ru(III)-complex [Ru(III)-L2] ligated by the ionic diphosphine (L2) proved efficient toward this tandem reaction. In Ru(III)-L2, the strong π-acceptor nature of L2 guaranteed Ru-center remaining in +3 valence state without redox reaction. Hence, Ru(III)-L2 was able to behave as a bifunctional catalyst merging RuIII-P complex and RuIII Lewis acid, which acted not only as a transition metal catalyst responsible for hydroformylation of olefins and hydrogenolysis of (hemi)acetals but also as a Ru3+ Lewis acid in charge of acetalization of aldehydes [to form (hemi)acetals]. The easily performed acetalization served as a bridge step to get through the pathway from aldehydes to alcohols instead of the direct hydrogenation.
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