We present a synthetic approach toward alloyed Cu/Zn nanoparticles using [Cu(OCH(Me)CH2NMe2)2] and Et2Zn as precursors. The thermolysis in the hot coordinating solvent hexadecylamine, HDA, leads to the formation of nanoscale, colloidal Cu/Zn systems with zinc contents (by EDX) of 5, 30, and 65%, respectively. All systems have been analyzed using UV/Vis spectroscopy, transmission electron microscopy, EDX, and selected area electron diffraction (SAED). These analytical data suggest that alloying between zinc and copper takes place, revealing crystalline phases of CuZn and CuZn2 besides Cu as components of the particles in the case of higher zinc concentrations. The characteristic surface plasmon resonance (UV) for pure HDA-capped copper colloids at 558 nm, still observed for copper-rich alloy particles, disappears for zinc-rich particles.

A novel, non-aqueous organometallic access to colloidal copper and copper/zinc (brass) nanoparticles is described. Hydrogenolysis of the precursor [CpCu(PMe 3 )] (1) in mesitylene at 150 uC and 3 bar H 2 quantitatively gives elemental Cu. Analogously, a solution of [ZnCp* 2 ] (2) reacts with H 2 to give elemental Zn in 100% yield. Co-hydrogenolysis of 1 and 2 in exactly equimolar quantities selectively yields the intermetallic phase b-CuZn characterised by powder X-ray diffraction (PXRD). Deep red colloidal solutions of nano-Cu as well as red to violet colloids of nano-brass alloys (a/b-CuZn) are obtained by co-hydrogenolysis of 1 and 2 in the presence of poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) as surfactant. All samples of the general formula Cu 12x Zn x (0.09 ¡ x ¡ 0.50) were characterised by means of elemental analysis, PXRD, transmission electron microscopy (TEM, EDX and SAED) and UV-Vis absorption spectroscopy. The presence and alloying of metallic Cu and Zn in the b-CuZn sample as a representative example of the series was confirmed by extended X-ray absorption fine structure spectroscopy (EXAFS). The oxidation behaviour of the nanoparticles was investigated by EXAFS, PXRD and UV-Vis spectroscopy indicating, that CuO x @Cu core-shell type particles were formed for pure copper particles, while in the case of brass particles preferential oxidation of the Zn component takes place, which results in core-shell particles of the type (ZnO) d @Cu 12x Zn x2d .

Free-standing, ZnO surface decorated Cu nanoparticles of 1-3 nm size were obtained by sequential co-pyrolysis of [Cu(OCHMeCH2NMe2)2] and ZnEt2 in squalane in the absence of additional surfactants and proved to be highly active quasi homogeneous catalysts for methanol synthesis from CO and H2.

A highly efficient one-step process to generate Cu-Zn colloids was developed, in which the colloidal particles were synthesized from Cu and Zn stearates by reduction with H(2) in a continuously operated stirred tank reactor. The resulting spherical, well separated particles have a size of 5-10 nm, consisting of a crystalline Cu(0) core (fcc) stabilized by a Zn stearate shell without long-range order. In situ attenuated total reflection FTIR spectroscopy was used to monitor the shift of the C-O stretching vibration of adsorbed CO as a function of temperature and pressure. The absence of the CO rotation-vibration bands of dissolved CO allowed us to obtain FTIR spectra at a CO pressure of 1.0 MPa at 473 K resulting in three shifted CO bands at 2030-2025, 1979-1978, and 1920 cm(-1). These bands indicate the presence of reduced coadsorbed Zn species on the metallic Cu surface. Cyclic CO adsorption experiments demonstrated the dynamics of the interaction between the Cu core and the Zn stearate shell.

High surface area ZnO nanoparticles are synthesized by applying a novel continuous precipitation method using a micromixer coupled directly to a bench-top spray dryer. The polycrystalline material is obtained by fast turbulent precipitation from aqueous zinc nitrate solutions with either sodium or potassium carbonate followed by immediate quenching of the aging due to the rapid water removal. Specific surface areas up to 98 m2 g-1 are obtained, depending on the precipitant and the sequence of unit operations applied after precipitation