The synthesis of two series of catalysts based on ligand-capped supported Pd nanoparticles was carried out using a simple procedure and the resulting materials were tested in the formate synthesis. Within these series, PPh 3 revealed the most appropriate stabilizing ligand while TiO 2 was the most efficient support for these catalysts. The hydrogenation of CO 2 was carried out under mild reaction conditions (1.8 MPa CO 2 , 1.8 MPa H 2 , 60 °C) using water as solvent and in the presence of a base, providing excellent selectivity towards formates with a TON of 1032 (TOF of 69 h À 1 , [HCOOK] = 1.1 mol/l).

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.

A straightforward method for the preparation of trisphosphinite ligands in one step, using only commercially available reagents (1,1,1-tris(4-hydroxyphenyl)ethane and chlorophosphines) is described. We have made use of this approach to prepare a small family of four trisphosphinite ligands of formula [CH3C{(C6H4OR2)3], where R stands for Ph (1a), Xyl (1b, Xyl = 2,6-Me2-C6H3), iPr (1c), and Cy (1d). These polyfunctional phosphinites allowed us to investigate their coordination chemistry towards a range of late transition metal precursors. As such, we report here the isolation and full characterization of a number of Au(I), Ag(I), Cu(I), Ir(III), Rh(III) and Ru(II) homotrimetallic complexes, including the structural characterization by X-ray diffraction studies of six of these compounds. We have observed that the flexibility of these trisphosphinites enables a variety of conformations for the different trimetallic species.

The optoelectronic properties of several Ag2S/graphene and FeS2/graphene nanostructures are examined through density functional theory calculations including dispersion forces. First, we analyzed the electronic structure of Ag2S and FeS2 nanocluster models, as prototypes of quantum dots, focusing on the electronic structure and absorption spectra. In the case of FeS2 nanoparticle, both ferro- and antiferromagnetic arrangements were considered. Then, Ag2S and FeS2 nanoclusters were adsorbed on top of both graphite and graphene slab models to study the stability of the systems as well as the effect of the nanocluster–surface interaction in the electronic structure, including an insight into the electron injection mechanisms in these systems. Finally, interface models, consisting of Ag2S or FeS2 thin films adsorbed on a graphene layer, were built and their optoelectronic properties examined. Overall, the results obtained in this work, support the suitability of these systems for their usage in solar cells. Graphical abstract